In order to explore, whether the surface structure affects the nucleation process, we investigated ALD of HfS2 on a differently oriented cobalt oxide film, namely on CoO(111). CoO(111) switches from a rocksalt-type to wurtzite-type stacking at the surface due to polarity compensation. As a result, CoO(111) exhibits metallic character and is oxygen-terminated with cobalt ions located slightly below the surface. Water does not adsorb in molecular form on CoO(111) but dissociates at a few defect sites forming strongly bound OH groups. The ALD experiments on CoO(111) were performed under exactly the same conditions and with the same measurement procedures as on CoO(100) (see Section 3.1). The recorded set of IR spectra was again plotted in the form of difference spectra (spectrum(n)spectrum(n-1)). The corresponding data is shown in Figure . The integrated area of the CH region for each spectrum is depicted in Figure . Apparently, HfS2 nucleates and grows very efficiently on CoO(111) as well, as indicated by the appearance and disappearance of the characteristic signals (2873, 2829, 2780, 1485 -1430, 1252, 1140, 1060 and 952 cm -1 ). As for ALD of HfS2 on CoO(100), the reaction with TDMAH is again faster than the reaction with D2S. This is to be expected as only the reaction with the pristine substrate in the first half cycle should show a different behavior. The data further indicates that the surface is fully saturated from the first cycle on, as we do not observe any noticeable difference in peak area between cycles (Figure ). This suggests a homogeneous growth of HfS2 which is surprising considering the structure of CoO(111). Taking into account that the CoO(111) is oxygen-terminated , we would expect cobalt sites to be less accessible on CoO(111) than on CoO(100) which features oxygen and cobalt ions in the same plane. However, we previously studied the reaction of carboxylic acids on CoO(111) and showed that carboxylate groups are formed and are able to bind to cobalt ions in the surface. We concluded that the surface cobalt ions in CoO(111) (which are located only slightly below the surface oxygen ions) can rearrange to bind to an adsorbate species.. This observation suggests that also on the CoO(111) surface, Lewis acid sites are available for a reaction with the precursor.