Synthesis and characterisation of Ga-doped hexagonal BaTiO3

被引：20

作者：

Feteira, A

Keith, GM

Rampling, MJ

Kirk, CA

Reaney, IM

Sarma, K

Alford, NM

Sinclair, DC

机构：

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

[2] S Bank Univ, Dept EEIE, London SE1 0AA, England

来源：

CRYSTAL ENGINEERING | 2002年 / 5卷 / 3-4期

基金：

英国工程与自然科学研究理事会;

关键词：

perovskites; electrical properties; dielectric materials BaTiO3;

D O I：

10.1016/S1463-0184(02)00055-2

中图分类号：

O6 [化学];

学科分类号：

0703 ;

摘要：

The hexagonal polymorph of BaTiO3 (P6(3)/mmc) has been stablished at room temperature by partial replacement of Ti by Ga, where BaTi1-yGayO3-y/2 and 0.06less than or equal toyless than or equal to0.125 for samples prepared at 1300degreesC. The unit cell expands with increasing y and Rietveld Refinement of Neutron diffraction data shows that oxygen vacancies occur only in the hexagonal close packed layers between the face-sharing Ti2O9 dimers. Exaggerated grain growth (> 100 mum) Occurs for ceramics processed at greater than or equal to1400degreesC and/or for sintering periods 2 hours. Electrical measurements show the materials to be electrically insulating with room temperature permittivity values of similar to70-80. Dense ceramics (94-97% of the theoretical X-ray density) resonate at microwave frequencies with Q.f values of similar to4000-8000 at similar to5.5 GHz. (C) 2003 Elsevier Science Ltd. All rights reserved.

引用

页码：439 / 448

页数：10

共 12 条

[1] REFINEMENT OF HEXAGONAL BATIO3 [J].