Oxygen Vacancy Defect Migration in Titanate Perovskite Surfaces: Effect of the A-Site Cations

被引：35

作者：

Brown, Joshua J. ^{[1
]}

Ke, Zhuofeng ^{[2
]}

Geng, Wei ^{[2
]}

Page, Alister J. ^{[1
]}

机构：

[1] Univ Newcastle, Prior Res Ctr Frontier Energy Technol & Utilisat, Callaghan, NSW 2308, Australia

[2] Sun Yat Sen Univ, Sch Chem & Chem Engn, MOE Key Lab Bioinorgan & Synthet Chem, Guangzhou 510275, Guangdong, Peoples R China

来源：

JOURNAL OF PHYSICAL CHEMISTRY C | 2018年 / 122卷 / 26期

基金：

澳大利亚研究理事会;

关键词：

DENSITY-FUNCTIONAL THEORY; SRTIO3; DIFFUSION; DISLOCATIONS; TRANSITION; MAGNETISM; POINTS; BULK;

D O I：

10.1021/acs.jpcc.8b03322

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

Oxygen vacancy formation energies and migration barriers in (001) surfaces of CaTiO3, SrTiO3, and BaTiO3 have been investigated using first principles density functional theory. The degree of distortion within the TiO2 sublattice in the presence of defects and consequently the defect formation energies in these titanate surfaces are determined by the size of the A-site cation (Ca2+ Sr2+ < Ba2+). This is notably the case for CaTiO3, in which the presence of a vacancy defect leads to a heavily distorted local orthorhombic structure within the (001) slab depending on the defect position, despite the overall cubic symmetry of the material modelled. This effectively leads to the TiO2 sublattice acting as a thermodynamic trap for oxygen vacancy defects in CaTiO3. By contrast, calculated vacancy diffusion pathways in SrTiO3 and BaTiO3 indicate that vacancy diffusion with these larger A-site cations is kinetically and not thermodynamically controlled.

引用

页码：14590 / 14597

页数：8

共 58 条

[1] Space group and crystal structure of the Perovskite CaTiO3 from 296 to 1720K [J].