Ab initio Study on Face Azimuth Dependency of Surface Energy and Structure in PbTiO3

Ab initio calculations were performed on five low-index surfaces of PbTiO3 with various terminations to investigate the face azimuth dependency of surface energy and structure. The result showed that the TiO2-terminated (100) surface is most stable at the condition of ab initio calculation (T = 0 K). However, the faceted structure consisting of not only (100) but also (210) and (211) is stable due to the relatively low surface energies of (210) and (211). It was predicted that large PbO-terminated (100) facets are formed at typical temperatures and oxygen pressures for the growth of PbTiO3 nanoscale structures.