Publication Date:
2020
Description:
〈h3〉Abstract〈/h3〉
〈p〉By means of the CRYSTAL computer program package, first-principles calculations of polar ZrO-, Ca- and O-terminated CaZrO〈sub〉3〈/sub〉 (011) surfaces were performed. Our calculation results for polar CaZrO〈sub〉3〈/sub〉 (011) surfaces are compared with the previous ab initio calculation results for ABO〈sub〉3〈/sub〉 perovskite (011) and (001) surfaces. From the results of our hybrid B3LYP calculations, all upper-layer atoms on the ZrO-, Ca- and O-terminated CaZrO〈sub〉3〈/sub〉 (011) surfaces relax inwards. The only exception from this systematic trend is outward relaxation of the oxygen atom on the ZrO-terminated CaZrO〈sub〉3〈/sub〉 (011) surface. Different ZrO, Ca and O terminations of the CaZrO〈sub〉3〈/sub〉 (011) surface lead to a quite different surface energies of 3.46, 1.49, and 2.08 eV. Our calculations predict a considerable increase in the Zr–O chemical bond covalency near the CaZrO〈sub〉3〈/sub〉 (011) surface, both in the directions perpendicular to the surface (0.240〈em〉e〈/em〉) as well as in the plane (0.138〈em〉e〈/em〉), as compared to the CaZrO〈sub〉3〈/sub〉 (001) surface (0.102〈em〉e〈/em〉) and to the bulk (0.086〈em〉e〈/em〉). Such increase in the B–O chemical bond population from the bulk towards the (001) and especially (011) surfaces is a systematic trend in all our eight calculated ABO〈sub〉3〈/sub〉 perovskites.〈/p〉
Print ISSN:
0022-2461
Electronic ISSN:
1573-4803
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
