无机材料学报

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铋掺杂铌镁酸铅陶瓷的制备及其有序现象研究

赵常雷; 冯楚德   

  1. 中国科学院上海硅酸盐研究所, 上海 200050
  • 收稿日期:1999-03-15 修回日期:1999-04-07 出版日期:2000-02-20 网络出版日期:2000-02-20

Fabrication and Ordering Behavior of Lead Magnesium Niobate Ceramics Doped with Bismuth Cations

ZHAO Chang-Lei; FENG Chu-De   

  1. Shanghai Institute of Ceramics; Chinese Academy of Sciences; Shanghai 200050; China
  • Received:1999-03-15 Revised:1999-04-07 Published:2000-02-20 Online:2000-02-20

摘要: 采用二步固相合成法制备钙钛矿相的掺铋铌镁酸铅陶瓷,利用XRD和TEM选区电子衍射技术对B位离子非计量有序排列结构进行了表征.研究表明,当为施主掺杂而提高Mg2+、Nb5+离子比例时,铌酸镁前驱体中逐渐出现六方MgNb相.施主Bi3+离子能够有效促进有序微区长大,提高系统有序度.利用X射线衍射线宽法对XRD慢扫描谱进行处理,求得当掺入5%Bi3+离子时,有序微区平均尺寸由纯PMN的5nm提高到22nm.

关键词: 铌镁酸铅, 有序微畴, 弛豫铁电体, 钙钛矿结构

Abstract: The pyrochlore-free Bi2O3 doped lead magnesium niobate ceramics were fabricated through columbite
precursor method and their B-site ordering structures were characterized by XRD and SAED techniques. With the increase of the ratio between
Mg2+ and Nb5+ cation content, hexagonal Mg4Nb9O6 becomes coexisting with orthorhombic MgNb2O6 in the columbite precursor.
The donor doping with Bi3+ can compensate for the space charge generated by the nonstoichiometric order and thus promotes the growth
of ordering regions. Moreover, the ordering degree of PMN can be increased pronouncedly with the increase of bismuth cation content
of the specimen. The average size of ordering microdomains estimated in PMN-0.05Bi specimen is about 22nm.

Key words: PMN, ordering microdomains, relaxors, perovskites

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