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Resistive switching memories (RRAMs) are attractive for replacement of conventional flash in the future. Although different switching materials have been reported; however, low-current operated devices (<100 μA) are necessary for productive RRAM applications. Therefore, TaOx is one of the prospective switching materials because of two stable phases of TaO2 and Ta2O5, which can also control the stable low- and high-resistance states. Long program/erase endurance and data retention at high temperature under low-current operation are also reported in published literature. So far, bilayered TaOx with inert electrodes (Pt and/or Ir) or single layer TaOx with semi-reactive electrodes (W and Ti/W or Ta/Pt) is proposed for real RRAM applications. It is found that the memory characteristics at current compliance (CC) of 80 μA is acceptable for real application; however, data are becoming worst at CC of 10 μA. Therefore, it is very challenging to reduce the operation current (few microampere) of the RRAM devices. This study investigates the switching mode, mechanism, and performance of low-current operated TaOx-based devices as compared to other RRAM devices. This topical review will not only help for application of TaOx-based nanoscale RRAM devices but also encourage researcher to overcome the challenges in the future production.
Keywords:Resistive switching; Memory; TaOx; RRAM
Semiconductor memory is an essential component of today's electronic systems. It is used in any equipment that uses a processor such as computers, smart phones, tablets, digital cameras, entertainment devices, global positioning systems, automotive systems, etc. Memories constituted 20% of the semiconductor market for the last 30 years and are expected to increase in the coming years [1]. Generally, memory devices can be categorized as 'volatile' and 'non-volatile' based on their operational principles. A volatile memory cannot retain stored data without the external power whereas a non-volatile memory (NVM) is the one which can retain the stored information irrespective of the external power. Static random access memory and dynamic random access memory (DRAM) fall into the volatile category, while 'Flash' which is the short form of 'flash electrically erasable programmable read-only memory' is the dominant commercial NVM technology. The requirements of an ideal NVM are high density, scalability, low cost, low-energy operation, and high performance for potential applications. Today's dominant memory technologies are DRAM and Flash, both have scaling issues. The DRAM offers very high endurance (approximately 1014 cycles); however, the endurance of Flash is limited (approximately 106 cycles), and the operation is slow as the program/erase time is relatively high (microseconds up to milliseconds). Generally, it needs high voltage for program and erase operations (>׀10 ׀V) [2,3]. In order to overcome these problems, other non-volatile memories such as ferroelectric RAM (FeRAM) [4,5], magnetic RAM (MRAM) [6,7], phase-change-memory (PCM) [8], and resistive RAM (RRAM) are being investigated [9-25]. The basic memories, prototypical, and emerging memories with respect to various performance parameters from International Technology Roadmap for Semiconductors (ITRS) in 2012 have been compared [26]. All these memories store data by resistance change in contrast to charge as in basic memories. In FeRAM, the polarization direction of the dipoles in the ferroelectric layer can be switched by applying the electric field which, in turn, leads the different memory states. MRAM utilizes the orientation of magnetization of a small magnetic element by the application of magnetic field which gives rise to the change in the electric resistance and enable data bits to be stored. Although, FeRAM and MRAM both have fast switching (<20 ns) and long endurance (>1015 cycles), these memories show insufficient scalability [27]. Moreover, MRAM needs high programming current (in the range of milliampere) [6]. Compared to FeRAM and MRAM, PCM offers greater potential for future application because of its better scalability [27]. In principle, PCM heats up a material changing it from low-resistance polycrystalline phase to a high-resistance amorphous phase reversibly. So in PCM, the generated heat, i.e., thermal effect, controls the switching. Due to this, the PCM cell needs more power for switching which limits its application in low-power devices. All memories discussed above are in production, though RRAM is at its early maturity level and it shows excellent potential to meet ITRS requirements for next-generation memory technology. Apart from its non-volatility, it shows good scalability potential below 10 nm. Some of the RRAM advantages are summarized in schematic diagram (Figure 1). Ho et al. [28] has demonstrated a 9-nm half-pitch RRAM device. They showed that if high-density vertical bipolar junction transistor will be used as a select transistor, it cannot provide the programming current required for PCRAM below 40 nm while for RRAM, it can be used even below 10 nm. Park et al. [20] reported sub-5-nm device in a Pt/TiO2/Cu structure. Ultra-high-speed operation of RRAM using atomic layer deposited HfO2 switching material is reported by Lee et al. [29], where a 300-ps pulse of only 1.4 V, successfully switches the device without any change in memory window. Torrezan et al. [21] also demonstrated the fast switching speed of 105 ps. Low energy consumption of only 0.1 pJ per operation [25] and multi-level data storage [16] required for high-density integration were reported. The energy consumption can be further reduced with increased reliability by scaling it to smaller dimensions [30]. Long pulse endurance of >1012 cycles is also demonstrated in TaOx-based crossbar device [31]. Other incentives of RRAM include its simple metal-insulator-metal (MIM) structure and good complementary metal-oxide-semiconductor (CMOS) compatibility. However, the poor understanding of the switching reliability, mechanism, low-current operation (<100 μA) are the bottlenecks in its further development and optimization. Overall, on the light of above discussion, RRAM is one of the most promising candidates for the replacement of flash in future. On the other hand, RRAM can also find its own application area, which will be more challenging and useful in the near future. Furthermore, the TaOx-based RRAM devices have been also reported extensively in the literature and shown good resistive switching performance. It is expected that this TaOx-based RRAM device has strong potential for production in near future. However, the TaOx-based RRAM devices with prospective and challenges have not been reviewed in literature yet.
Figure 1. Prospective of RRAM devices. Endurance, speed, scalability, and requirements of RRAM devices.
This topical review investigates the switching mode, mechanism, and performances of the TaOx-based devices as compared to other RRAMs in literature. Long program/erase endurance and data retention of >85°C with high yield have a greater prospective of TaOx-based nanoscale RRAM devices; however, lower current (few microampere) operation is very challenging for practical application, which is reviewed in detail here.
Resistive RAM overview
Resistance switching effect was first reported by Hickmott in 1962 [32] and had subsequently been observed by many researchers over the years [9-36]. RRAM is a two-terminal passive device in which a comparatively insulating switching layer is sandwiched between two electrically conducting electrodes, as shown in Figure 2. However, a working RRAM device generally consists of one transistor (1T) or one diode (1D) and one resistor (1R), i.e., 1T1R or 1D1R configurations. The resistance of the RRAM device can be altered by simply applying external bias across the MIM stack. The electrode on which a voltage or current is applied can be referred to as the top electrode (TE), and the other electrically grounded electrode can be called as the bottom electrode (BE).
Figure 2. Structure of RRAM device. Schematic diagram of RRAM in metal-insulator-metal structure and its biasing.
Switching modes: unipolar/bipolar
The resistance of a RRAM device can be modulated in two ways as shown by the current/voltage (I-V) curves in Figure 3. On the basis of I-V curves, the switching modes can be classified as unipolar (nonpolar) and bipolar. In unipolar resistive switching mode (Figure 3a), the switching direction does not depend on the polarity of the applied voltage and generally occurs at higher voltage amplitude that of bipolar switching. A pristine memory device with high initial resistance state (IRS) can be switched in to a low-resistance state (LRS) by applying a high voltage stress. This process is called the 'electroforming process' or simply 'forming process' and alters the resistance of the pristine device irreversibly [15,37]. Some RRAM devices do not need the forming process and are called forming-free devices. Forming-free devices are highly required for RRAM practical application and are reported infrequently [38-41]. After the forming process, the RRAM device can be switched to a high-resistance state (HRS), generally lower than that of the IRS by the application of a particular voltage called reset voltage. This process is called 'RESET process.' Switching from a HRS to a LRS called 'SET.' In the SET process, generally, the current is limited by the current compliance (CC) in order to avoid device damage. The resistive switching in unipolar mode has been observed in many highly insulating oxides, such as binary metal oxides [10]. The unipolar devices suffer from high non-uniformity and poor endurance. In bipolar resistive switching mode, the SET and RESET occur in the opposite polarity, i.e., if memory device can be set by applying positive voltage on TE, then only negative voltage can reset the device (Figure 3b). So, this type of resistive switching is sensitive to the polarity of the applied voltage. For bipolar switching to occur, the MIM stack should be asymmetric generally, such as different electrodes or a dedicated voltage polarity for the forming process. Many oxides show bipolar resistive switching and will be also discussed later. The devices in which unipolar and bipolar modes can be changed by changing the operation conditions are called 'nonpolar' devices [42], and the resistive switching mechanism is explained below.
Figure 3. Switching mode of the RRAM devices. (a) I-V curves for unipolar (nonpolar) switching where the switching direction is independent on the polarity of the applied voltage and (b) bipolar switching. In bipolar switching, SET and RESET occur at opposite polarity bias.
Resistive switching mechanism
Generally, depending on the conduction path, the switching mechanism can be classified as (1) filamentary-type and (2) interface-type, as shown in Figure 4. In the filamentary model, the switching originates from the formation/rupture of conducting filament in the switching material by the application of suitable external bias shown in Figure 4a [15,17]. The filamentary paths are formed under SET and ruptured under RESET. Electrochemical migration of oxygen ions and redox reaction near the metal/oxide interface is widely considered as the possible mechanism behind the formation and rupture of the filaments [43]. However, clear visualization of the conducting filaments in switching material has yet to be achieved. Studies involving high-resolution transmission electron microscopy showed the conducting filaments in different systems [24,44-48]; however, the switching mechanism is still clearly not understood. On the other hand, in the interface-type mechanism, the switching occurs at the interface of the metal and switching material, as shown in Figure 4b [49]. Several models have been reported for the driving mechanism involved in an interface-type conducting path, such as electrochemical migration of oxygen vacancies [50-53], trapping of charge carriers (hole or electron) [54,55], and a Mott transition induced by carriers doped at the interface [56-58]. To understand the difference between the filament and interface types of resistive switching, the area dependence of the RRAM device resistance could be examined. In general, if the resistance of the LRS is independent of the device area and HRS varies inversely, the switching is filamentary. When both LRS and HRS increase with decreasing device area, the switching is related to interface-type.
Further, depending on the switching material and electrodes, the resistive switching memory can be divided into two types: cation-based switching called electrochemical metallization (ECM) memory and anion-based switching called valance change memory (VCM) [17]. In cation-based memory, a solid-electrolyte was used as a switching material and an electrochemically active metal such as copper (Cu), silver (Ag), and Nickel (Ni) as TE and an inert metal as BE [17]. Generally, the ions of Cu and Ag were known as mobile ions. When positive voltage was applied on the Cu TE, for example, metallic Cu was reduced electrochemically to give Cu+ ions generated from metallic Cu due to anodic dissolution. These ions then diffused through the solid electrolyte due to electric field and reached to the BE where these ions reduced to become metallic Cu and electro-crystallize on the BE. As a result, a conducting filament grew preferentially from the BE and finally bridge the BE and TE. Consequently, the device switched to the LRS. That is the reason that ECM devices were also called conducting bridge RAM. When negative voltage was applied on the TE electrode, the Cu filament broken due to electrochemical dissolution reaction initiated by an electronic current through the metallic bridge, and, in parallel, an electrochemical current and the device came into HRS. In recent years, many solid electrolyte materials such as GeSex[11,59,60], GeS [61,62], Cu2S [63], Ag2S [64], Ta2O5[65,66], SiO2[67], TiO2[68], ZrO2[69], HfO2[70], GeOx[48], MoOx/GdOx[71], TiOx/TaSiOy[72], GeSex/TaOx[46], CuTe/Al2O3[73], and Ti/TaOx[22] were reported. The VCM devices consist of a sub-stoichiometric switching material and an inert electrode such as Pt, Ir, Au, etc., or reactive electrode such as W, Al, Ti, Ni, etc. In VCM devices, switching occurs due to the redox reaction induced by anion (O2-) migration to form conducting filament, as shown in Figure 4a. These devices usually need a forming step in order to switch between LRS and HRS reversibly [17,21]. During electroforming process, the generation of oxygen O2- ions occurs in the switching material due to chemical bond breaking. The generated O2- ions migrate toward the TE under the external bias, and oxygen gas evolution at the anode due to anodic reaction are also reported in literature. To maintain the charge neutrality, the valance state of the cations changes. Therefore, it is called VCM memory. Due to O2- ion generation and anodic reaction, oxygen vacancy conducting path generates in the switching material between TE and BE, and device switches to LRS. The electroforming conditions strongly depend on the dimension of the sample, in particular, the switching material thickness. In addition, thermal effects play an essential role in the electroforming, and it sometimes damage the devices by introducing morphological changes [17,21]. Partially blown electrodes during forming have been observed [17]. Thus, the high-voltage forming step needs to be eliminated in order to product the RRAM devices in future. However, anion-based switching material with combination of different electrode materials and interface engineering will have good flexibility to obtain proper RRAM device.
RRAM materials
Resistance switching can originate from a variety of defects that alter electronic transport rather than a specific electronic structure of insulating materials, and consequently, almost all insulating oxides exhibit resistance switching behavior. Over the years, several materials in different structures have been reported for RRAM application to have better performance. The switching materials of anion-based devices include transition metal oxides, complex oxides, large bandgap dielectrics, nitrides, and chalcogenides. Table 1 lists some of the important materials known to exhibit resistance switching for prospective applications. Few of them reported low-current operation <100 μA only, which is very challenging for real applications in future. Among other various metal oxides such as NiOx[74-76], TiOx[77-81], HfOx[29,38,82-86], Cu2O [87], SrTiO3[43,88], ZrO2[89-92], WOx[28,30,93], AlOx[94-97], ZnOx[39,98-101], SiOx[102,103], GdOx[104,105], Pr0.7Ca0.3MnO3[15,106], GeOx[107,108], and tantalum oxide (TaOx)-based devices [31,109-128] are becoming attractive owing to their ease of deposition using existing conventional systems, high thermal stability up to 1,000°C [115], chemical inertness, compatibility with CMOS processes, and high dielectric constant (ϵ = 25). Moreover, Ta-O system has only two stable phases of Ta2O5 and TaO2 with large solubility of O (71.43 to 66.67 at.%) above 1,000°C in its phase diagram [129]. This property of TaOx is important in order to achieve long switching endurance (the longest reported endurance of >1012 cycles is from TaOx-based device [31]). It has a metastable and comparatively conducting TaO2 phase. Further, the absolute value of Gibbs free energy for redox (reduction-oxidation) reaction of TaOx is low which shows its better stability [109]. The redox reaction is written in Equation 1 below.
Table 1. Switching materials and SET/RESET current in published literature
A schematic potential energy curve for TaOx is reported by Wei et al. [109]. This implies that both the HRS and the LRS of TaOx are stable owing to small difference of Gibbs free energy in between LRS and HRS, and the barrier height between these states is quite high. Due to these benefits of TaOx switching material, it is important to design RRAM for real application. That is why this material has been studied in this review below.
Resistive RAM using TaOx material
A small via size of 150 × 150 nm2 of the W/Ti/TaOx/W and W/TaOx/W structures was fabricated [41]. A high-κ Ta2O5 film with a thickness of ≈7 nm was then deposited by an e-beam evaporator. Then, a thin Ti (≈3 nm) interfacial layer by rf sputtering was deposited. The final devices were obtained after a lift-off process. Memory device structure and thicknesses of all layers were observed by transmission electron microscopy (TEM) with an energy of 200 keV. Figure 5a shows a typical cross-sectional TEM image of the W/TaOx/W structure. The device size is 150 × 150 nm2. The thickness of TaOx layer is 6.8 nm (Figure 5b). Figure 6a shows TEM image of the W/TiOx/TaOx/W structures. The thicknesses of the TiOx and TaOx layers are approximately 3 and 7 nm, respectively. Both films show an amorphous characteristics outside (Figure 6b) and inside (Figure 6c) regions of the via-hole. The device size is approximately 0.6× 0.6 μm2. As Ti removes oxygen from the Ta2O5 film in the W/TiOx/TaOx/W structure, the film becomes more oxygen-deficient TaOx, which is very important to achieve an improved resistive switching. XPS analyses were carried out to determine the oxidation states of all layers after the fabrication process, and the resulting spectra are presented in Figure 7[22,114]. The spectra were simulated using Gaussian-Lorentzian functions. The peak binding energies of Ta2O5 4f7/2 and Ta2O5 4f5/2 electrons for the Ta2O5/W structure were centered at 26.7 and 28.6 eV, respectively (Figure 7a), and the binding energies of Ta 4f7/2 and Ta 4f5/2 electrons were centered at 21.77 and 23.74 eV, respectively. This suggests that the high-κ Ta2O5 film mixed with Ta metal, resulting in a TaOx layer where x< 2.5. This may be due to the reaction of oxygen with the bottom W layer during deposition of the Ta2O5 film. It is very interesting to note that the area ratios of the Ta 4f7/2 and Ta 4f5/2 peaks with respect to the area of the Ta2O5 4f7/2 peak are both 0.03 for the TaOx/W structure, while those of the TiOx/TaOx/W structure are 0.27 and 0.16, respectively (Figure 7b). This means that the Ta content of the TiOx/TaOx/W structure was higher than that of the TaOx/W structure. Furthermore, the binding energy of TiO2 2p3/2 in Ti/TaOx/W structure is 459.57 eV (Figure 7c). As Ti removes oxygen from the Ta2O5 film, the film becomes the more oxygen-deficient TaOx, which is vital to achieve improved resistive switching. The peak binding energies of the W 4f7/2, WO3 4f7/2, W 4f5/2, and WO3 4f5/2 electrons of the TaOx/W structure are centered at 31.6, 36.2, 33.9, and 38.3 eV, respectively (Figure 7d). The area ratios of the WO3 4f7/2 and WO34f5/2 spectra with respect to the area of W 4f7/2 are both 0.03 for the TaOx/W structure, while those for the TiOx/TaOx/W structure are 0.27 and 0.16, respectively (Figure 7e). This suggests that W can be oxidized at the TaOx/W interface when a Ti layer is not present, resulting in a TaOx/WOx/W structure which may have inferior resistive switching properties. When a Ti layer is deposited on the TaOx film, the W layer is prevented from oxidizing at the TaOx/W interface, leading to the formation of a TiOx/TaOx/W structure. Considering the Gibbs free energies of TiO2, Ta2O5, and WO3 films, which are -887.6, –760.5, and -506.5 kJ/mol, respectively, at 300 K [130], the Ti will consume the highest oxygen content owing to its stronger reactivity than those of the other materials, thereby forming Ta-rich (or defective TaOx) film. This also prevents oxidation of the W TE at the TaOx/W interface owing to the migration of oxygen from the underlying films toward the Ti film, which contributes to the improved resistive switching memory performance as described below.
Figure 5. TEM image of W/TaOx/W structure. (a) Cross-sectional TEM image with a device size of 0.15 × 0.15 μm2. (b) HRTEM image inside the via-hole region. The thickness of TaOx film is approximately 6.8 nm.
Figure 6. TEM image of W/TiOx/TaOx/W structure. (a) Cross-sectional TEM image with a typical device size of 0.6 × 0.6 μm2. HRTEM images of (b) outside and (c) inside via-hole regions.
Resistive switching memory characteristics are explained here. Figure 8 shows current/voltage and resistance-voltage characteristics. The W/TiOx/TaOx/W device exhibits >1,000 consecutive repeatable dc switching cycles with a better resistance ratio of 102 under a low CC of 80 μA, the W/TaOx/W device shows few switching cycles with a higher CC of 300 μA [41]. In this case, negatively charged oxygen ions (O2-) migrate from the switching material toward W TE, and this has a lesser possibility to form an oxygen-rich layer at the W TE/TaOx interface, leading to the formation of multi-conduction filaments. However, the insertion of a thin (≈3 nm) Ti layer in between the W and TaOx layers in the W/TiOx/TaOx/W device makes a vast difference because Ti can be used as an oxygen reservoir. A repeatable switching of >10,000 cycles is also observed [41]. Under 'SET,' O2- rather than oxygen vacancies will migrate from TaOx toward the TE, resulting in a TiO2 layer which controls the conducting vacancy filament diameter in the TaOx layer by controlling current overflow and producing a tighter distribution of the LRS. Owing to this series resistance, the devices exhibit non-ohmic current. It is true that the conducting filament is formed through the TaOx film. When negative voltage is applied to the TE, oxygen ions are pushed from the TiO2 layer toward the conducting filament where they recombine with oxygen vacancies or oxidize the conducting filament. The device will be in HRS. Control of oxygen-deficient filament formation and rupture is facilitated by insertion of the thin Ti layer at the TE/TaOx interface, which results in repeatable and reproducible resistive switching characteristics, which has very good prospective of TaOx-based resistive switching memory in a W/TiOx/TaOx/W structure for real application. Some other reported results have been explained below.
Yang et al. [110] has reported the Pt/TaOx/Ta device with a diameter of 100 μm, where Pt was grounded and external bias was on the Ta electrode. Long program/erase (P/E) endurance of 1.5 × 1010 cycles with a pulse width of 1 μs is reported. Further, a comparison of endurance characteristics made between TiOx and TaOx-based devices (Figure 9) shows far better performance by TaOx-based devices stretching the P/E cycles to >109 cycles (Figure 9b) as compared to only 104 cycles for TiOx-based devices and it is collapsed finally (Figure 9a). The reason having longer endurance in TaOx devices is the presence of only two solid stable phases in bulk equilibrium with each other and large oxygen solubility in Ta-O system which can act as the source/sink of mobile ions for switching in the insulating phase as compared to many Magneli phases in Ti-O system [110]. The operation current could be reduced to 100 μA. The underlying switching mechanism is attributed to the redox reaction resulting insulating Ta2O5 and conducting Ta(O) solid solution. The energy-filtered TEM (EFTEM) zero-loss images and oxygen map of the switching region confirm also the reduction of TaOx thickness by half in the active region, and the oxygen content in the reduced region is found as low as that in the Ta electrode. The switching phenomenon is believed to be due to oxygen vacancies and ions through nano-ionic transport and a redox process, and this can be called VCM [17]. A schematic diagram was shown in Figure 10a [31,41,43,131-133]. As suggested previously, an intrinsic Schottky barrier exists between the Pt TE and the Ta2O5-x layer contact while in the insulating state, and an ohmic contact is formed in the LRS. This suggests that oxygen ion movement under external bias leads to the LRS to HRS or HRS to LRS. Lee et al. [31] reported TaOx-based crossbar resistive switching memory device. Figure 10b shows the scanning electron microscopy (SEM) image. The device stack consists of Pt top and bottom electrode and bilayer TaOx switching layer with insulating Ta2O5-x layer near TE and TaO2-x near BE as can be seen in the cross-section TEM image presented in Figure 10c. They fabricated the devices with different sizes from 50 × 50 μm2 to 30 × 30 nm2. All size devices have shown self-compliance bipolar switching with small set/rest voltage of -1.0/2.0 V. The switching current of 50 × 50 μm2 device was >200 μA and for 30 × 30 nm2 device was approximately 40 μA, respectively (Figure 10d). From the I-V switching curves, this is a symmetric current profile when the device is in the LRS, but it is an asymmetric current profile for the HRS. This property was exploited to realize RRAM devices in crossbar architecture without any selection device with anti-serial connection. They were also able to achieve the highest ever reported endurance value of 1012 for this system at 30 × 30 μm2 cell size for base layer oxidation of 3%. Data retention of >10 years at 85°C was also reported. To eliminate the need for a discrete switch element such as a diode or transistor, they connected two Pt/Ta2O5-x/TaO2-x/Pt cells antiserially by external contacts and this concept was also reported by Linn et al. [134].
Figure 10. Schematic of switching mechanism and I-V characteristics of cross-point memory devices. (a) Schematic representation of the TaOx device consisting of a thin Ta2O5-x insulating layer and a TaO2-x base layer. The movement of internal oxygen ions or vacancies is used to model the switching. (b) SEM image of a 30-nm crossbar array of devices with the inset showing a single device. (c) TEM cross-section of a 30-nm crossbar cell. The total thickness of TaOx layer is 30 nm. (d) I-V hysteresis characteristics [31].
Wei et al. [109] explored first the prospective application of TaOx-based RRAM devices. The memory stack consisted of Pt top and bottom electrodes and a non-stoichiometric switching layer of TaOx. The first layer near the TE is close to insulating Ta2O5-x phase, while the other layer is close to TaO2-x phase which is conducting. The memory device with a size of 0.5 × 0.5 μm2 in 1T1R configuration showed bipolar switching characteristics under an operation current of approximately 170 μA. The device shows excellent P/E endurance of >109 cycles. The data retention property could be improved under low-current operation by controlling the size of the conductive filament as well as percolation paths, while the density of oxygen vacancy is kept high enough. It is true that the conducting filament size can be scaled down by reducing both the forming current and formation. A forming voltage can be decreased with a thinner switching layer. However, the thinnest layer is not required because this will have lower HRS. Figure 11a shows a pulsed R-V curve of the two-step forming to control the formation of conducting filament size in Ir/Ta2O5-δ/TaOx resistive memory stack [120]. At first (or step 1), a positive pulse that has the same polarity for the RESET is applied to generate oxygen vacancies in the Ta2O5-δ layer, as shown in Figure 11b. The resistance of the switching material decreases drastically from the initial resistance state (IRS: approximately 15 MΩ); however, it stays at HRS (200 to 500 kΩ), as shown in red line. Second (or step 2), a negative pulse is applied to create the conducting filament at LRS (approximately 20 kΩ). A negative forming voltage, which determines the conducting filament size, is reduced from 2.6 to 1.1 V with a 100-ns pulse width. However, a conventional negative forming voltage (-2.6 V) is shown in blue line, this changes HRS (approximately 15 MΩ) to LRS (approximately 10 kΩ). Quantum-size effect and percolation models of RESET for different switching materials have been explained to understand the conducting filaments [135,136]. Another method of reducing CC can be used to control the conducting filament size, which can be achieved by adjusting the resistivity of the bulk TaOx layer. The resistivity can reduce the forming current by controlling the oxygen content of TaOx[120]. In this case, the conducting filament size becomes smaller and oxygen vacancy becomes larger when the oxygen content is increased. The observed switching is due to the change of barrier height on the application of voltage. When positive voltage was applied, O2- ions migrate from bulk and accumulate near the TE. Oxidation reaction increases the barrier height and device comes to the HRS. On the other hand, when negative voltage was applied on the TE, O2- ions move away from TE and reduction reaction lowers the barrier height which brings the device into LRS. Hence, the barrier height change on the application of bias voltage due to redox reaction is responsible for the observed switching. Several kinds of electrode materials were examined and found that the materials having high work function show stable resistance switching behavior. The significant improvement in the retention characteristics at 150°C under the small current operation of 80 μA by two-step forming are obtained as compared to single-step forming. Two-step electroforming process is very critical to have controlled conducting filament diameter as well as the RRAM could be operated as low current at 80 μA. The W/TiOx/TaOx/W memory device showed good bipolar resistive switching characteristics with different CCs from 10 to 100 μA (Figure 12[41]). The low-resistance state decreases with increasing CCs from 10 to 100 μA (Figure 12a,b), which will be useful for multi-level data storage applications. As the filament diameter increases with higher CCs, the low-resistance state decreases, and the value of RESET voltage increases. The RESET current can be scaled down to 23 μA at a low CC of 10 μA. Figure 13a,b shows the device-to-device uniformity of LRS/HRS and SET/RESET voltage, respectively. The cumulative probability distribution is small for both LRS/HRS as well as set/reset voltage. The resistance ratio of HRS/LRS is >100, and the device can be operated below ±5 V. The device can be switched more than 104 AC cycles with stable LRS, as shown in Figure 14a. The device has also shown good read endurance of >105 times at a read voltage of 0.2 V (Figure 14b). No read disturbance is observed during whole course of testing. Figure 15a shows the data retention characteristics at high temperature of 85°C under small switching current of 80 μA. Good data retention of both the states is obtained for >104 s with memory margin of >102. Considering the obtained nano-filament diameter of approximately 3 nm [41], a high density of approximately 100 Tbit/in2 is obtained. This device has shown also data retention of few minutes at a very low current of only 10 μA, as shown in Figure 15b. The resistance ratio is gradually decreased with elapsed time. Table 2 compares data published in literature for TaOx-based resistive switching memories [16,31,41,83,85,109,120] and other materials [137-140]. It is found that TaOx-based resistive switching devices is one of the comparative materials with other switching materials; however, the low-current operation is published a few papers. This suggests that the TaOx-based RRAM devices with low-current operation are a big challenging for real application, which needs to be studied in future.
Figure 11. Electroforming process and filament diameter control. (a) Pulsed resistance-voltage curve of the two-step forming scheme (red) compared with the common forming scheme (blue). Small conducting filament formation is confirmed by its high resistance after step 2. (b) Schematics of the Ta2O5-δ resistive switching layer during the two-step forming process. Oxygen vacancies are generated in the Ta2O5-δ layer after step 1, and a conducting filament is formed by applying a negative pulse in step 2 [120].
Figure 12. Current/voltage hysteresis with different current compliances. I-V hysteresis characteristics (a) LRS and reset currents (b) with 10- to 100-μA CCs. A device could be operated with a low reset current of 23 μA [41].
Figure 13. Statistical data plot. Cumulative probability plots of (a) LRS and HRS and (b) SET and RESET voltage.
Figure 14. Endurance characteristics. (a) AC endurance of >104 cycles and (b) long read pulse endurance of >105 cycles at a read voltage of 0.2 V.
Figure 15. Data retention characteristics. (a) Good data retention of >104 s with a good resistance ratio of >102 at 85°C under CC of 80 μA and (b) the resistance ratio gradually decreases with retention time at a low CC of 10 μA.
Table 2. Data comparison in published literature
It is reviewed that TaOx-based bipolar resistive switching memory could be operated at a low current of 80 μA [41,109], which has prospective of RRAM applications in the future. Further, TaOx is a simple and useful material because of two stable phases of TaO2 and Ta2O5, as compared to other reported materials. Long program/erase endurance of >1010 and 10 years data retention are also reported in published literature [31,110]. So far, bilayered TaOx with inert electrodes (Pt and/or Ir) or single-layer TaOx with semi-reactive electrodes (W and Ti/W or Ta/Pt) are reported; however, conducting nano-filament formation/rupture is controlled by oxygen ion migration through bilayered or interfacial layer design under external bias. Further, high-density memory with a small size of 30 × 30 nm2 could be designed using crossbar architecture [31]. It is found that the memory performance is becoming worst at operation current of 10 μA. Therefore, it is very challenging to reduce the operation current (few microampere) of the RRAM devices. So far, good performance of TaOx-based resistive switching memory devices is investigated, as compared to other switching materials in different RRAMs. This topical review shows good prospective; however, it needs to overcome the challenges for future production of the TaOx-based nanoscale RRAM application.
Competing interests
The authors declare that they have no competing interests.
Authors' contributions
This work was supported by the National Science Council (NSC), Taiwan, under contract numbers: NSC-101-2221-E-182-061 and NSC-102-2221-E-182-057-MY2. The authors thank Electronic and Optoelectronic Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan, for their experimental support.
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Mickel PR, Lohn AJ, Choi BJ, Yang JJ, Zhang M-X, Marinella MJ, James CD, Williams RS: A physical model of switching dynamics in tantalum oxide memristive devices.
Appl Phys Lett 2013, 102:223502. Publisher Full Text
Schmelzer S, Linn E, Bottger U, Waser R: Uniform complementary resistive switching in tantalum oxide using current sweeps.
Lee D, Woo J, Cha E, Kim S, Lee W, Park S, Hwang H: Interface engineering for low power and uniform resistive switching in bi-layer structural filament type ReRAM.
Kim S, Kim S-J, Kim KM, Lee SR, Chang M, Cho E, Kim Y-B, Kim CJ, In Chung U: Physical electro-thermal model of resistive switching in bi-layered resistance-change memory.
Zhuo VYQ, Jiang Y, Li MH, Chua EK, Zhang Z, Pan JS, Zhao R, Shi LP, Chong TC, Robertson J: Band alignment between Ta2O5 and metals for resistive random access memory electrodes engineering.
Appl Phys Lett 2013, 102:062106. Publisher Full Text
Elliman RG, Saleh MS, Kim TH, Venkatachalam DK, Belay K, Ruffell S, Kurunczi P, England J: Application of ion-implantation for improved non-volatile resistive random access memory (ReRAM).
Yang Y, Choi S, Lu W: Oxide heterostructure resistive memory.
Nano Lett 2013, 13:2908. PubMed Abstract | Publisher Full Text
Garg SP, Krishnamurthy N, Awasthi A, Venkatraman M: The O-Ta (oxygen-tantalum) system.
J Phase Equil 1996, 17:63. Publisher Full Text
Birks N, Meier GH, Pettit FS: Introduction to the high-temperature oxidation of metals. Cambridge: Cambridge University Press; 2006.
http://www.doitpoms.ac.uk/tlplib/ellingham_diagrams/interactive.php webcite
Fujimoto M, Koyama H, Konagai M, Hosoi Y, Ishihara K, Ohnishi S, Awaya N: TiO2 anatase nanolayer on TiN thin film exhibiting high-speed bipolar resistive switching.
Appl Phys Lett 2006, 89:223509. Publisher Full Text
Hur JH, Lee M-J, Lee CB, Kim Y-B, Kim C-J: Modeling for bipolar resistive memory switching in transition-metal oxides.
Yoshida C, Kinoshita K, Yamasaki T, Sugiyama Y: Direct observation of oxygen movement during resistance switching in NiO/Pt film.
Appl Phys Lett 2008, 93:042106. Publisher Full Text
Linn E, Rosezin R, Kugeler C, Waser R: Complementary resistive switches for passive nanocrossbar memories.
Nat Mater 2010, 9:403. PubMed Abstract | Publisher Full Text
Long S, Lian X, Cagli C, Cartoix X, Rurali R, Miranda E, Jimenez D, Perniola L, Ming Liu M, Sune J: Quantum-size effects in hafnium-oxide resistive switching.
Appl Phys Lett 2013, 102:183505. Publisher Full Text
Long S, Cagli C, Ielmini D, Liu M, Sune J: Analysis and modeling of resistive switching statistics.
J Appl Phys 2012, 111:074508. Publisher Full Text
Terai M, Sakotsubo Y, Saito Y, Kotsuji S, Hada H: Effect of bottom electrode of ReRAM with Ta2O5/TiO2 stack on RTN and retention. In Tech Dig - Int Electron Devices Meet. Baltimore, MD; 2009:1-4.
Chen YS, Lee HY, Chen PS, Liu WH, Wang SM, Gu PY, Hsu YY, Tsai CH, Chen WS, Chen F, Tsai MJ, Lien C: Robust high-resistance state and improved endurance of HfOx resistive memory by suppression of current overshoot.
Govoreanu B, Kar GS, Chen Y, Paraschiv V, Kubicek S, Fantini A, Radu IP, Goux L, Clima S, Degraeve R, Jossart N, Richard O, Vandeweyer T, Seo K, Hendrickx P, Pourtois G, Bender H, Altimime L, Wouters DJ, Kittl JA, Jurczak M: 10 × 10nm2 Hf/HfOx crossbar resistive RAM with excellent performance, reliability and low-energy operation. In Tech Dig - Int Electron Devices Meet. Washington, DC; 2011:31.6.1-31.6.4.
Chien WC, Chen YR, Chen YC, Chuang ATH, Lee FM, Lin YY, Lai EK, Shih YH, Hsieh KY, Chih-Yuan L: A forming-free WOx resistive memory using a novel self-aligned field enhancement feature with excellent reliability and scalability. In Tech Dig - Int Electron Devices Meet. San Francisco, CA; 2010:19.2.1-19.2.4.


text:
The only words that can come out of my mouth right now are "what a fucking tool". I'm not a violent person by nature but this picture makes me want to punch him in the balls. Fucking.Tool.
When will this douchebag die already! Don't Italians live to be about 30. Or was I just hoping?
I'm Italian so I'd say no but I'm sure Charles Darwin has a theory about people like him….
Can people stop paying this guy to host parties so he can start hosting at Applebee's like he was always fated to do?
Word. Specifically a Staten Island Applebee's.
Oh god please!!!
Move: Weston Cage paparazzi karate demo
These tools time is almost over and the best part is they have zero talent or skills so there is no chance of them turning up and doing concerts in malls or reunion shows like the Backstreet Boys or any other boy bands.
… So then they asked me if I was flexible, and I was like, of course I'm fucking flexible, I'm the Situation. I dunno what that has to do with baseball though… anyhow, they hired me as their new catcher on the spot!
are we fucking done with this guy and his band of herpes-laden umpa-lumpas yet?
What a choice, does one go to his party or Kim's? Doesn't really matter, whichever one you go to will prominently feature a giant ass.
Weston Cage is looking a lot dorkier these days.
what a feeling!
So this is what it looks like to jump the shark.
Pissed off, The Situation tries to explain why they misspelled Shateau.
Jesus, he still exists?
Move: Charm necklace twistabout.
Well, I guess if we do inspect his crotch from *this close* we might find something…
Move: Riverdance Crotch Whistle
It looks like he's wearing pajama jeans.
Imitation is the highest form of douche baggery.
"I should have thrown that bannana peel farther away. If only I could evolve…"
I thought he was dead. Seriously.
Muhfucker can't even goose-step right.

subset: commoncrawl


text:
On 5 December 2012, as part of a global rebranding of Chartis to AIG, "Chartis Europe Limited" - Greek Branch and its legal representative in Greece "Chartis Greece Representation of Insurance Enterprises SA"wererenamed to "AIG Europe Limited" - Greek Branch and "AIG Greece Representation of Insurance Enterprises SA" respectively.
AIG Europe Limited is a part of AIG, a leading international insurance organisation serving customers in more than 130 countries. AIG companies serve commercial, institutional and individual customers through one of the most extensive worldwide property-casualty networks of any insurer.
Other than the change in name, this change will not affect our clients or policyholders in any way. It does not impact the terms and conditions of our insurance policies or the ability to claim. The same teams will continue to provide expert underwriting and claims handling services.
We look forward to continuing to insure you.


text:
Apple seeds third iOS 5, iTunes 10.5 betas, final Xcode 4.1
updated 02:20 pm EDT, Mon July 11, 2011
Joined by third Xcode 4.2 preview
Apple is now seeding the third betas of iOS 5 and iTunes 10.5, reports indicate. The latter is required to sync with devices running iOS 5 beta 3, which can include the iPad 1 and 2, the iPhone 3GS and 4 (GSM/CDMA), and the third- and fourth-generation iPod touch. A new iOS 5 release is also available for Apple TVs.
iOS improvements so far appear to be limited to the correction of some bugs. New issues have been identified as well, such as app scripts failing to run on their first try after a reboot or clean install of the firmware. Wi-Fi sync may be unreliable.
On the programming end Apple has pushed out two new versions of the Xcode suite. The first is the gold master of v4.1, meaning that an official release should be imminient. Developers can also experiment with Xcode 4.2 preview 3, which should solve trouble with Organizer, as well as memory use connected to IPSWs.


text:
- Filed Under
I like to save money on clothes just as much as anyone else does, so let's talk clothing prices. Specifically, reader Blake would like to know why larger clothing sizes cost a few dollars more than the standard sizes.
Dear Jill,
When shopping for shirts, whether T-shirts or casual button-down shirts, I can wear XL, but for comfort I prefer to buy XXL. Why do the companies that make or sell these shirts price XL and XXL $2 more than the S, M and L sizes? Is there that much more material used from L to XL or XXL? It seems that they are discriminating against us larger-sized consumers. I am not fat, but I am ...


text:
LAS CRUCES — It's been a dream that lifelong Las Crucen Tito Lujan has had for more than 40 years.
"Mesilla has one. Shoot, even (the unincorporated village of) Doña Ana has one," Lujan sighed. "Why can't Las Cruces have one, too. It makes sense. Most places in the state have one except Las Cruces. It's way over due; it's about time."
Lujan was referring to downtown plaza, a gathering place where residents could sit and talk on sunny mornings or warm evenings. A place Lujan envisions where fiestas could be staged, or outdoor concerts or other entertainment events.
It's the same vision numerous other Las Crucens have shared with Lujan. The pluses of a civic plaza have far outweighed any concerns that have been raised to this point.
"It's only going to benefit Las Cruces," Karla Garcia said. "The people want it. It should happen."
There's a possibility it could happen sooner rather than later.
No one is willing to talk on the record yet, but that could potentially change in the coming weeks. Apparently, negotiations are either about to happen or might have already started toward securing a location for the proposed plaza. Years ago, city officials tried to work out a deal to acquire a drive-through motor bank property, owned by Bank of the West, at the northeast corner of Griggs Avenue and Main Street.
However, city and bank officials could never come to terms on a deal and the property is still owned by the bank.
When negotiations between the city and Bank of the West began in the early 2000s, City Manager Robert Garza — then an assistant city manager, was the city's primary point of contact on the negotiations. After providing the then-City Council with an update on the status of those preliminary negotiations, they suddenly ceased. Except for the inability to come to a mutually agreeable sales price for the property, no other specific reasons were disclosed.
But there was a general assumption among interested residents that once city officials publicly disclosed how negotiations were proceeding that disclosure might have led to the halt of negotiations.
"I haven't heard any more," said Garza, about the resumption of the negotiations. "We're supposed to meet soon with representatives of the Las Cruces Community Partnership (LCCP), who is working with the city to help market downtown properties. Hopefully, we'll have a better idea of where things stand after that meeting. Depending on what they have to tell us, we could be ready to go forward if something could be reached."
The meeting between Garza and LCCP is supposed to happen late this week.
Garza added circumstances for the city have changed since those initial negotiations years ago. The city has a fairly lengthy list of downtown properties it owns that possibly could become factors in negotiations. An important sticking point in preliminary discussions was the bank's ability to keep it's downtown drive-through bank facility operating. Years ago, there was a proposal the bank could convert a portion of its parking lot, outside of the bank, at the northeast corner of Main Street and Las Cruces Avenue, into a drive-through banking facility with access onto Main Street for its customers.
But Garza hinted there might be a possibility the city could consider swapping downtown property it owns with the bank. Among those properties might be the former City Hall building, 400 N. Church St., which is across the street and just east of Bank of the West. The former City Hall has been vacant for almost three years, since city government moved into new offices at 700 N. Main St. in April 2010.
"It's a possibility, something now that might be a consideration," said Garza, of a potential land swap. "The city has said on numerous occasions that it would consider disposing of properties on its inventory list."
Steve Ramirez can be reached at 575-541-5452. Follow him on Twitter @SteveRamirez6
Civic plaza
• City administrators and elected city officials have made the establishment of a civic plaza in downtown Las Cruces a priority.
• Conceptual designs and phases of such a plaza have been developed.
• City officials have identified a preferred location of a civic plaza at the northeast corner of Griggs Avenue and Main Street. However, that property is currently privately owned.
• Cost estimates to build a civic plaza have fluctuated because of the price of land and changing — mostly rising — construction costs.
• City officials have considered the notion of creating a civic plaza for at least 10 years.
• A civic plaza would be a major component of downtown revitalization efforts in Las Cruces.
• Conceptual designs, information and details about a proposed civic plaza in downtown Las Cruces: http://extras.mnginteractive.com/live/media/site557/2013/0228/20130228_062807_Conceptual_civic_plaza1.pdf
• Additional information and background on a proposed civic plaza: http://extras.mnginteractive.com/live/media/site557/2013/0228/20130228_063102_Conceptual_civic_plaza2.pdf
• General information about incorporating the concept of a civic plaza in downtown Las Cruces: http://extras.mnginteractive.com/live/media/site557/2013/0228/20130228_063449_Conceptual_civic_plaza3.pdf;
• Las Cruces Downtown Partnership website: http://downtownlascruces.org/


text:
Iowa Women's Archives
University of Iowa Libraries
Iowa City, Iowa
0.5 linear inches
Iowa Women's Archives
100 Main Library
University of Iowa Libraries
Iowa City, Iowa 52242
Phone: 319-335-5068
Fax: 319-335-5900
E-mail the Iowa Women's Archives
The papers (donor no.757 ) were donated by Joe Girard in 2001.
The papers are open open for research.
Copyright held by the donor has been transferred to The University of Iowa.
Processed by:
Margaret Richardson and Lisa Mott, 2004. [ GirardMadge.doc]
Madge Lula Clark was born on July 25, 1904 in Granger, Iowa to Edward Clark and Dora Hotchkiss Clark. Clark had two brothers, Harry and Avery, and a sister, Clara. In 1909 the Clark family moved to Lemmon, South Dakota. Clark was educated in country schools, graduating from Lemmon High School in 1923. In 1925, Clark married Hamilton Eugene Girard in Aberdeen, South Dakota. The couple had two children, a son, Joe, and a daughter, Beverly. The Girards moved to Des Moines, Iowa in 1939. In 1943 the family moved to Rolfe, Iowa where the Girards operated a Super Valu grocery store for many years. Hamilton Girard died in 1951. Madge Girard continued to make her home in Rolfe until 1997, when she moved to Humboldt, Iowa. Girard died on September 28, 2000.
Scope and Content Note
The Madge Clark Girard papers date from 1972 to 1991 and measure 0.5 linear inches. The papers consist of a copy of a memoir Girard wrote between 1972 and 1984, with an additional passage written in 1991. [The original memoir is housed in Iowa State University Special Collections Department] The memoir tells of Girard's childhood and early life homesteading in South Dakota. Her memories include reminiscences of the country schools she attended, church services, social gatherings, and Christmas programs. The memoir also includes information on both the Clark and Girard family histories. In addition to Girard's memoir, there is a brief synopsis of the work composed by Margaret Richardson, Iowa Women's Archives volunteer.
Girard, Madge Clark (1 folder)
general information | history and mission | collections | reference services | news and events | home
For more information about this collection contact the Iowa Women's Archives.
Last updated June 4, 2004.


text:
Download SUM Program CD Lite
The SUM Program for Medical Transcription Training downloadable Lite version contains all the functionality of the actual SUM Program software, but has only one active report for each SUM unit. You can use the software and listen to the dictations without the foot pedal required for the actual SUM Program software.
Please download The SUM Program CD Lite software. (20 MB)


text:
>Sonora / Tuolumne News, Sports, & Weather, Angels Camp, Twain Harte, Jamestown | Union Democrat
The Sheriff's Office reported the following:
12:48 p.m., East Sonora — A 49-year-old woman was arrested on suspicion of public intoxication, after someone said she spilled a can of beer outside of a store on the 13700 block of Mono Way and left it there.
2:37 p.m., Twain Harte — A woman on the 17900 block of Robin Road said someone accessed her e-mail account, found her credit card information and used it for their benefit.
4 p.m., Sonora area — Someone on the 14100 block of Alder Lane said an unknown person used their Visa number and spent $163. Three charges were made in Las Vegas and one in Indiana.
5:10 p.m., Columbia — A person said their house on the 11000 block of State Street was ransacked and burglarized when they returned home. The burglars made away with several items including medication, an Xbox, video games, a Nintendo Wii, and a laptop computer.
7:16 p.m., East Sonora — Unknown suspects used a counterfeit $20 bill to purchase food from Taco Bell on the 13700 block of Mono Way.
The Sonora Police Department reported the following:
2:43 p.m., suspicious circumstances — Someone reported second-hand information that there were .22 caliber shells outside the door of the cafeteria and gym at Sonora High School. Officers responded and found the shells, but there was no damage to the school.
5:32 p.m., public intoxication — A 28-year-old man was arrested on suspicion of public intoxication, after he was reported to the police for walking around the parking lot of a liquor store on South Washington Street and asking people for money.
The Sheriff's Office reported the following:
9:22 a.m., San Andreas — Vandalism occurred at an apartment complex on Lewis Avenue.
2:55 p.m., Jenny Lind — Burglary to a residence occurred on Chardonnay Place, which turned out to be unfounded.
8:35 p.m., Arnold — People were fighting in the parking lot of a bar on Highway 4.
Cited on suspicions of driving while under the influence of alcohol or drugs:
7:25 p.m., San Andreas — Jodi Merenda, 35, of Jackson, was arrested near the 100 block of West St. Charles Street.
The Union Democrat is now online in a Replica E-edition form and publishes Tuesday through Saturday. E-Edition or Print Plus subscribers have full access.
If you are not a current subscriber, subscribe today for immediate access. Circulation: 209-533-3614
Weekly Arts and entertainment guide for Calaveras and Tuolumne counties
Available online every Friday or get it early in Thursday's print edition.


text:
|Reviews for Eternal Goodbye
| writerwithheart chapter 1 . 5/3
I love Reth/Evie so much but Lend/Evie wins out in my book every time, however this was truly beautiful and I thank you so much for it, I needed it. 3 3 3
| xXSennaXx chapter 1 . 8/8/2013
Finally a Reth fan! :) I felt like I was the only one haha...
Anyways, I really enjoyed this...very, very much. I feel like you captured Reth's feelings very well. This is exactly how I imagined him being since he seemed to keep his feelings locked up and just show Evie what she thought about him.
I'm really bad at reviews but I hope this made sense. :)
| Aaryanna Spinks chapter 1 . 6/6/2013
Wow, that was really good. I love Reth so much! *cries because he can't be real, and I will never see him* I can't wait for the movie!
| hannahstrawberry chapter 1 . 1/24/2013
THIS BROKE MY HEART EVEN MORE THAN READING IT FROM EVIE'S POINT OF VIEW IN THE BOOK DID. I will ship Evie/ Reth until I die.
| Elena Mikaelson chapter 1 . 1/13/2013
Why can't Evie and Reth be together! I love that couple and compared to Evie and Reth, I hate Evie and Lend
| yay chapter 1 . 1/13/2013
I think this was pretty cute.
| Moonshadow15000 chapter 1 . 12/22/2012
;-; This made me cry so much. Reth is my favorite character so you're not the only one who enjoys Reth/Evie.
| ResidentEvilChris chapter 1 . 12/12/2012
RETH! I love Reth so much! hes an amazing character, and I love Evie/Reth!
| Guest chapter 1 . 12/2/2012
amazing... that was incredible! i loved it, i mean it was also sad, but i loved it at the same time!
| rellimmes chapter 1 . 11/23/2012
ok, i'm torn- i love Evie's devotion to Lend, but then again I really like Reth's devotion to Evie- you made both sides of the story sound great, thank you!
| Sara chapter 1 . 11/5/2012
I loved this SOO much! It's great to know that I wasn't the only person who liked Evie/Reth more than Lend. I was so sad when he left, I wish he stayed with Evie!


text:
Robert Galbraith Heath
Dr. Robert Galbraith Heath (9 May 1915 – 24 September 1999) was an American psychiatrist. He followed the theory of biological psychiatry that organic defects were the sole source of mental illness,[1] and that consequently mental problems were treatable by physical means.
Heath founded the Department of Psychiatry and Neurology at Tulane University, New Orleans, in 1949 and remained its chairman until 1980.[2] He performed many experiments there involving electrical stimulation of the brain via surgically implanted electrodes.[3][4] This work was partially financed by the CIA and the US military.[5]
Heath also experimented with the drug bulbocapnine to induce stupor, using prisoners in the Louisiana State Penitentiary as experimental subjects.[6] He later worked on schizophrenia, which he regarded as an illness with a physical basis.[7]
See also[edit]
External links[edit]
- Septal stimulation for the initiation of heterosexual behavior in a homosexual male. Journal of Behavior Therapy
- Pleasure and brain activity in man: deep and surface electroencephalograms during orgasm. Journal of Nervous and Mental Disease
- ^ Heath, R.G. (1961) Reappraisal of biological aspects of psychiatry. Journal of Neuropsychiatry 3: 1-11.
- ^ In Memoriam: Robert Galbraith Heath, MD, DMSci (1915–1999). Neurology 54(2): 286.
- ^ Heath, R.G. (1963) Electrical self-stimulation of the brain in man. American Journal of Psychiatry 120: 571-577.
- ^ Moan, C.E., & Heath, R.G. (1972) Septal stimulation for the initiation of heterosexual activity in a homosexual male. Journal of Behavior Therapy and Experimental Psychiatry 3: 23-30.
- ^ "Robert Heath at Wireheading". Wireheading.com. 1977-08-02. Retrieved 2013-07-27.
- ^ Scheflin, A.W. & Opton, E.M. (1978) The Mind Manipulators: a non-fiction account. (Paddington Press: New York) ISBN 0-448-22977-3 pp. 314-315.
- ^ Heath, R.G. (1967) Schizophrenia: pathogenetic theories. International Journal of Psychiatry 3(5): 407-10.


text:
Some severe storms moving through central Kentucky have caused damage in parts of the area.
Hail seems to be a big issue.
We saw some hail on the ground as big as tennis balls in Nicholas County.
Cars seemed to take the brunt the damage caused by the hail.
Many cars in Nicholas County now have big dents, and many windshields were shattered.
Amy Mastin was on the road when a storm moved through.
She says she's grateful to have escaped without injury.
"We were between Carlisle and Millersburg, and it hit us while we were driving, just in time to go into shelter," Mastin said.
People in Millersburg, in Bourbon County, also reported damage caused by hail.


text:
The very first article at cjvlang back in 2000 was Days of the Week in Chinese, Japanese, and Vietnamese. I don't remember why I chose the topic, but I soon found myself drawn deeper and deeper into an ancient, confusing, and complex subject. In those pre-Wikipedia days it was still a lot of fun finding information, online and off, and putting it together to create something that no one had done before, at least on the Internet. Twelve years later, Wikipedia has scooped just about everything into its capacious maw and it's a challenge to find new angles to explore. Tempted though I was to extend Days of the Week to Mongolian, there was little to add to what was already found at places like the China History Forum, which, while containing many errors and misapprehensions, basically covered the territory. It would be a tough job coming up with content that no one else had done before.
That was until a recent exchange at Language Hat prompted me to look more closely at Buryat. When I did, I made the curious discovery that, unlike Mongolian proper, Buryat is one of that small group of languages that explicitly treats Sunday as the first day of the week. Of course, the Buryat names are listed at the exhaustive geonames.de list, but despite this, no one appears to have commented on this peculiarity. After that, a bit more casual digging around revealed that Inner Mongolians had their own version of the names of days of the week which are seldom found on the Internet (although this Japanese-language blog does carry them). It was clearly time to tackle a page on Days of the Week in Mongolian and Buryat.
The page that eventually took shape mostly repackages the usual information about Tibetan and Indian planetary names that is available elsewhere. But the Inner Mongolian and Buryat names ensured it had a unique angle that no one had covered before – the similarities and differences among the three sets of numbered days (Inner Mongolian, Mongolian, and Buryat). Unfortunately, it is hard to come up with a fully satisfactory explanation for the three formats and their differences.
The three sets of names are as follows:
|Inner M.
|бүтэн сайн өдөр
büteŋ saiŋ ödör
|гарагийн өдөр
garagiŋ ödör
|гарагай нэгэн
garagaj negen
|нэгдэх өдөр
negdekh ödör
|гарагийн нэгэн
garagiŋ negeŋ
|гарагай хоёр
garagaj ȟojor
|хоёрдахь өдөр
khoyordakh' ödör
|гарагийн хоёр
garagiŋ khoyor
|гарагай гурбан
garagaj gurban
|гуравдахь өдөр
guravdakh' ödör
|гарагийн гурван
garagiŋ gurvaŋ
|гарагай дүрбэн
garagaj dürbän
|дөрөвдэх өдөр
dörövdekh ödör
|гарагийн дөрвөн
garagiŋ dörvöŋ
|гарагай табан
garagaj taban
|тавдахь өдөр
tavdakh' ödör
|гарагийн таван
garagiŋ tavaŋ
|гарагай зургаан
garagaj zurgaan
|хагас сайн өдөр
khagas saiŋ ödör
|гарагийн зургаан
garagiŋ zurgaaŋ
|гарагай долоон
garagaj doloon
For the weekdays, the names are formed according to the following pattern, using Monday as an example:
Mongolian: negdekh ödör (нэгдэх өдөр; 'first day')
Inner Mongolian: garagiŋ negeŋ (гарагийн нэгэн; 'one of the week')
Buryat: garagaj ȟojor (гарагай хоёр; 'two of the week')
The word garag/garig (гараг/гариг) has as its original meaning 'planet', but thanks to the Tibetan-based names for days of the week it has come to mean 'day of the week' and, going further, 'week'. (This incidentally, fairly clearly indicates that the Tibetan names came first and the numbered names were formed later.)
The genitive form garagiŋ (гарагийн – Inner Mongolian) or garagaj (гарагай – Buryat) can be interpreted as '…of the week', yielding the meanings '(day) one of the week' and '(day) two of the week' respectively. This is completely parallel to the system of dates in Mongolian. For instance, the first of October is aravdugaar sariŋ negen аравдугаар сарын нэгэн '(day) one of number-ten month'.
As I noted above, the Mongolian names count the days of the week from Monday as 'day one'. By contrast, the Buryat names count the days of the week from Sunday as 'day one'.
The relationship of the three sets of weekday names can be summed up in the following table:
|Monday start
|Sunday start
|Genitive of гараг/гариг + number
|Inner Mongolian
Only one variety shares features with both of the others: Inner Mongolian, which shares the 'genitive of гариг / гараг + a numeral' format with Buryat, and the custom of counting from Monday with Mongolian. Mongolian and Buryat have in common only the fact of counting.
Saturday and Sunday
For Saturday and Sunday, each variety has its own peculiarity.
* Buryat simply includes the two days in the total counting sequence. They become '(day) seven of the week' and '(day) one of the week' respectively.
* Inner Mongolian uses '(day) six of the week' for Saturday, and garagiŋ ödör (гарагийн өдөр; 'day of the week') for Sunday. The latter is a calque on the somewhat meaningless Chinese term xīngqītiān (星期天) or xīngqīrì (星期日), literally 'week day' or 'day of the week'. The original Chinese term was the more meaningful lǐbàitiān (礼拜天 / 禮拜天) 'day of worship'. The term xīngqītiān results from substituting a new word for 'week', xīngqī, in place of the original lǐbài (meaning 'worship' and 'week').
* Mongolian of Mongolia calls Saturday the 'day of half rest' and Sunday the 'day of rest'.
Common source for Mongolian?
For Inner Mongolian, these names are quite clearly modelled on the Chinese names for days of the week, which use a similar series based on xīngqī 星期 'week' (Monday= xīngqīyī 星期一 'week one', Tuesday= xīngqī'èr 星期二 'week two', etc.). This goes right through to the day for Sunday, modelled on xīngqī'tiān 星期天.
But the relationship with the other two is hard to explain. The use of a different format in Mongolia is not insurmountable. Indeed, there is a dictionary – a Chinese-Mongolian dictionary that is notable for not giving the most idiomatic or widely used forms — that lists a hybrid form. For example, Monday is given as garagiŋ negdekh ödör = гарагийн нэгдэх өдөр 'first day of the week'. For the weekdays, at least, the hybrid form combines the Inner Mongolian, Mongolian, and Buryat styles, i.e., the genitive of гараг/гариг plus an ordinal. This hybrid form could be either 1) the source of the two different forms, which subsequently diverged in the two areas, or 2) a deliberate attempt to artificially bridge the gap. The fact that two territories which use the genitive of гариг / гараг are separated by Mongolia, which doesn't, suggests that the two territories represent the older form and that it is Mongolia that has diverged. Although I have no hard historical data to back it up, it thus seems quite possible that the Inner Mongolian and Mongolian numbered names share this hybrid form as a common source, probably dating back to the late Qing. Needless to say, however, it is quite possible that there is another, quite different explanation.
The difference with Buryat is more problematic. Although the Buryat area was under Russian control at the time the days of the week became established in China (late 19th century), the use of the genitive of гараг/гариг could easily have diffused into Buryat-speaking areas from Mongolian-speaking areas to the south. What is truly puzzling, however, is the divergence of the starting day for counting in Buryat. Old Turkic counted the days from Sunday, too, and the western Buryat dialects were heavily influenced by Turkic. But given that Old Turkic broke up by the 13th century, it would be a long shot indeed to propose an Old Turkic origin for the Buryat usage. At this stage I have no explanation for this phenomenon.
Names in East Asia
The Mongolian page adds a further twist to the names used in East Asian languages. To summarise:
* The Japanese revived names that they borrowed from Chinese a millennium ago.
* The Chinese common people came up with their own names based on contact with missionaries. This naming was not to the taste of the literate class, resulting in the emergence of two later sets of names that were felt to be more 'elegant'.
* The Vietnamese names were introduced by Portuguese missionaries and were based on the preferred names of the Catholic Church.
* The Mongolian planetary names were introduced from Tibet, but the numbered systems in popular use possibly arose later under Chinese influence. The divergent numbering system of the Buryat names is a mystery.
The possible Chinese origin of the Mongolian names is not something that many Mongolians would welcome, and is thus a candidate for one of the overlooked 'angles' turned up in the course of doing the subsite. While I can't lay claim to having discovered them, these angles certainly made it worthwhile putting the information together in the way that I did. They include:
- The common custom in Western European languages of naming the days after gods causes many people lose sight of one important fact: the days are supposed to be named after planets, not gods. The Germanic names (including English) are actually anomalous in not referring to the planets. The Japanese and Mongolian planetary names are closer to the original concept than the English names are.
- The lǐbài (礼拜/禮拜) names in Chinese were the earliest forms in modern usage, with the xīngqī (星期) names and the zhōu (周/週) names coming later. This is obvious from comparing lǐbàitiān (礼拜天/禮拜天) 'day of worship' with xīngqītiān (星期天) 'week day', as I noted above. The rather meaningless xīngqītiān 'week day' is derived from the more meaningful lǐbàitiān 'day of worship'. This hunch was brilliantly born out by a Chinese-language paper I discovered after I did the page, which gave dates and historical data.
- Supposedly reputable Chinese references distort the facts in order to support the 'official line'. This is evident in the bias against lǐbài (because it smacks of an introduced religion), the strong implication that the planetary names really originated in China, and the implication that xīngqī is descended from these ancient precedents despite being a modern coinage. It is unfashionable to trot out cultural stereotypes such as 'the Chinese like to claim that almost everything originated in China', but in this case it may fairly be said that Cihai has literally been caught in the act.
- The Vietnamese names were from Portuguese and reflected the preferred usage of the Catholic church, but the name chúa nhật 'Lord's Day' was deliberately changed to chủ nhật 'Main Day' by the Buddhists. This was achieved quite effortlessly by simply giving the chu nom character 主 chúa 'master, lord' its alternative reading of chủ 'main, chief, principal, lord'.
- Some unknown person in the Japanese Meiji government (it would be nice to know who!) hit on the idea of using old planetary names for the days of the week. These old names had been borrowed from Chinese and kept alive for many generations. This was an inspired choice that may seem natural in retrospect but was by no means a foregone conclusion.
- In a modern-day manifestation of the 19th century urge to datsu-a nyū-ō (脱亜入欧="get out of Asia, get into Europe"), one of the Japanese sources I used bent over backwards to deny that the Japanese names were actually borrowed from Chinese.
Perhaps I am perverse, but I find debunking the cultural prejudices that tend to obscure or subtly de-emphasise the facts – the assumption that English is closer to the naming tradition than languages of the Far East; the attempt by Chinese reference books to trace recently coined names back to ancient Chinese origins; Japanese attempts to show that their names essentially came from Europe, not China; the aversion of Vietnamese Buddhists to the Catholic naming system; and a general Mongolian blindness to possible Chinese influence in their culture – the most interesting angle of all.


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Park City — www.nationalparkstraveler.com%2F" title="http://click.icptrack.com/icp/relay.php?r=30338383&msgid=92008&act=SBQ7&c=1378153&destination=http%3A%2F%2Fwww.nationalparkstraveler.com%2F">National Parks Traveler, a website dedicated to daily editorial coverage of the national parks, has launched Parkipedia, which is modeled after Wikipedia, the crowd-sourced online encyclopedia.
Parkipedia was launched along with a redesign of the eight-year-old Traveler's website. Central to that redesign was creation of a "members area" for readers who, for $9.95 a year, become Traveler members.
As with Wikipedia, entries to Parkipedia can be contributed and edited by all Traveler members. Details on hiking, lodging, dining, activities and supporting photographs on all aspects of national park visits can be contributed by Traveler members.
"Printed guidebooks, sadly, are dinosaurs of sorts in today's digital world," said Kurt Repanshek, Traveler founder and editor-in-chief, who has authored multiple guidebooks. "The time it takes to research, write, and print them almost makes them obsolete by the time they're published."
While many printed park guides are researched and written by one or two people, Traveler's Parkipedia guides are collaboratively written by the people who time and again visit their favorite parks and have amassed years of knowledge in the areas of hiking, wildlife, camping, lodging and more.
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