Review of Systematic Tendencies in (001), (011) and (111) Surfaces Using B3PW as Well as B3LYP Computations of BaTiO<sub>3</sub>, CaTiO<sub>3</sub>, PbTiO<sub>3</sub>, SrTiO<sub>3</sub>, BaZrO<sub>3</sub>, CaZrO<sub>3</sub>, PbZrO<sub>3</sub> and SrZrO<sub>3</sub> Perovskites

oleh: Roberts I. Eglitis, Ran Jia

Format: Article
Diterbitkan: MDPI AG 2023-12-01

Deskripsi

We performed B3PW and B3LYP computations for BaTiO<sub>3</sub> (BTO), CaTiO<sub>3</sub> (CTO), PbTiO<sub>3</sub> (PTO), SrTiO<sub>3</sub> (STO), BaZrO<sub>3</sub> (BZO), CaZrO<sub>3</sub> (CZO), PbZrO<sub>3</sub> (PZO) and SrZrO<sub>3</sub> (SZO) perovskite neutral (001) along with polar (011) as well as (111) surfaces. For the neutral AO- as well as BO<sub>2</sub>-terminated (001) surfaces, in most cases, all upper-layer atoms relax inwards, although the second-layer atoms shift outwards. On the (001) BO<sub>2</sub>-terminated surface, the second-layer metal atoms, as a rule, exhibit larger atomic relaxations than the second-layer O atoms. For most ABO<sub>3</sub> perovskites, the (001) surface rumpling <i>s</i> is bigger for the AO- than BO<sub>2</sub>-terminated surfaces. In contrast, the surface energies, for both (001) terminations, are practically identical. Conversely, different (011) surface terminations exhibit quite different surface energies for the O-terminated, A-terminated and BO-terminated surfaces. Our computed ABO<sub>3</sub> perovskite (111) surface energies are always significantly larger than the neutral (001) as well as polar (011) surface energies. Our computed ABO<sub>3</sub> perovskite bulk B-O chemical bond covalency increases near their neutral (001) and especially polar (011) surfaces.