Energetics of Donor-Doping, Metal Vacancies, and Oxygen-Loss in A-Site Rare-Earth-Doped BaTiO3

被引：69

作者：

Freeman, Colin L. ^{[1
]}

Dawson, James A. ^{[1
]}

Chen, Hung-Ru ^{[1
]}

Ben, Liubin ^{[1
]}

Harding, John H. ^{[1
]}

Morrison, Finlay D. ^{[1
,2
]}

Sinclair, Derek C. ^{[1
]}

West, Anthony R. ^{[1
]}

机构：

[1] Univ Sheffield, Dept Mat Sci & Engn, Sheffield S1 3JD, S Yorkshire, England

[2] Univ St Andrews, Sch Chem, St Andrews KY16 9ST, Fife, Scotland

来源：

ADVANCED FUNCTIONAL MATERIALS | 2013年 / 23卷 / 31期

基金：

英国工程与自然科学研究理事会;

关键词：

doping; semiconductors; electroceramics; computer simulations; BARIUM-TITANATE CERAMICS; DEFECT CHEMISTRY; SIMULATION; CRYSTAL; LATTICE;

D O I：

10.1002/adfm.201203147

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The energetics of La-doping in BaTiO3 are reported for both (electronic) donor-doping with the creation of Ti3+ cations and ionic doping with the creation of Ti vacancies. The experiments (for samples prepared in air) and simulations demonstrate that ionic doping is the preferred mechanism for all concentrations of La-doping. The apparent disagreement with electrical conduction of these ionic doped samples is explained by subsequent oxygen-loss, which leads to the creation of Ti3+ cations. Simulations show that oxygen-loss is much more favorable in the ionic-doped system than undoped BaTiO3 due to the unique local structure created around the defect site. These findings resolve the so-called donor-doping anomaly in BaTiO3 and explain the source of semiconductivity in positive temperature coefficient of resistance (PTCR) BaTiO3 thermistors.

引用

页码：3925 / 3928

页数：4