"Figure [in shows the evolution of Raman spectra obtained for powders annealed at various temperatures". The plots are "typical depolarized scattering profiles for single and polycrystalline BaTiO3" . The Raman active phonons of tetragonal P4mm crystal symmetry are represented by 3A1+B1+4E. "Long-range electrostatic forces induce the splitting of transverse and longitudinal phonons, … The detailed phonon assignments are indicated on the spectrum", in the Fig. (j) by Shiratori et al. "It is well known that the BaTiO3 tetragonal phase reveals Raman scattering bands at around 250, 520 and 720 cm -1 and a sharp peak at around 306 cm -1 . On the other hand, … Although the cubic phase theoretically does not reveal any Raman active modes, this polymorph generally shows broad bands at around 250 and 520 cm -1 , which may be caused by local disorder associated with the position of Ti atoms". "The raw powder emits a very intense background, which is probably fluorescence originating from the organic residues … a mixture of Raman scattering features for cubic and tetragonal BaTiO3 can be observed at around 297, 523 and 720 cm -1 ". Note that the inset of Fig. (a) is showing a Raman spectrum processed by a baseline correlation. The proposed spectrum "indicates that the as-synthesized powder is already crystallized in a mixture of a dominant cubic and a very minor tetragonal portion since the intensity of the tetragonal features is very low" . The observed spectrum at 1 bar agrees well with the powder Raman spectrum reported by Burns and Scott and also with those reported for ceramic and polycrystalline films grown by metal-organic chemical vapor deposition" (Venkateswaran et al., and references therein). "It compares well with the single crystal data except for a dip near 186 cm -1 which has been understood as an interference due to the anharmonic coupling between the three A1(TO) phonons"; in a note Venkateswaran and coworkers write that "the dip at 186 cm -1 has been observed in [their] samples when the Rayleigh tail at low frequencies was reduced considerably".