Journal of South China University of Technology (Natural Science Edition) ›› 2005, Vol. 33 ›› Issue (2): 1-5.

    Next Articles

Preparation and Properties of La-Doped BaTiO3 Ceramics(Ⅰ)：By a Heterogeneous Nucleation Processing Technique

Zhuang Zhi-qiang  Su Tao-long  Liu Bo   

  1. College of Materials Science and Engineering,South China Univ.of Tech.,Guangzhou 510640,Guangdong,China
  • Received:2004-04-20 Online:2005-02-25 Published:2005-02-25
  • Contact: 庄志强(1945-)，男，教授，博士生导师，主要从事电子材料与元器件方面的研究 E-mail:tszhuang@scut.edu.cn
  • About author:庄志强(1945-)，男，教授，博士生导师，主要从事电子材料与元器件方面的研究
  • Supported by:

    广东省自然科学基金资助项目(020951)

PDF

451

Abstract:

Hvdrothermally-synthesized barium titanate powders were coated with La(OH)3 through a heterogeneous nucleation processing technique with La(NO3)3 as the La source.The pH value during the heterogeneous nuclea-tion was calculated based on the theory of solubility product. By controlling the pH value in dispersed BaTiO3 sus-pension, La2O3-coated BaTiO powders and ceramics with a homogeneous and stoicheometry composition of (Ba1-3x/2M/La )TiO3 were then prepared. Meanwhile,the influence of La content on the sintering behaV or,phaLse structure.resistivity and dielectric constant-temperature dependence of the La-doped BaTiO3 ceramics added with SiO2 was discussed. Expe:rimental results demonstrate that the La-doped BaTiO3 ceramics with homogeneous and stoicheometry composition CaD．easily be prepared by the doping method mentioned above· It is also found that the Curie temperature of the prepared BaTiO3 ceramics decreases linearly with the increase of La2 O3 content,and that more La is needed to make a BaTiO semicondsucting ceramic derived from the method than by an oxide-mixing re-action method.

Key words: barium titanate, lanthanum, ceramic, heterogeneous nucleation, deposition, coating