无机材料学报

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PMN-PT单晶与陶瓷在性能及相变方面的特点

王评初; 罗豪甦; 李东林; 潘晓明; 陈辛尘; 殷之文   

  1. 中国科学院上海硅酸盐研究所, 上海 200050
  • 收稿日期:2000-01-17 修回日期:2000-02-24 出版日期:2001-01-20 网络出版日期:2001-01-20

Characters of Piezoelectricity and Phase Transition of PMN-PT Single Crystals and Ceramics

WANG Ping-Chu; LUO Hao-Su; LI Dong-Lin; PAN Xiao-Ming; CHEN Xin-Chen; YIN Zhi-Wen   

  1. Shanghai Institute of Ceramics; Chinese Academy of Sciences; Shanghai 200050; China
  • Received:2000-01-17 Revised:2000-02-24 Published:2001-01-20 Online:2001-01-20

摘要: 着重介绍了用Bridgman方法生长的(1-)Pb(Mg1/3Nb2/3)O3-PbTiO(PMN-PT)固溶体单晶在介电、压电、热释电性能及相变方面的一些特点:①异常高的压电常数33(高达3000pC/N以上),耦合系数(在0.6以上),33(达0.90),高的介电常数(高达5000甚至更高),低的值(约60),热释电系数也较高.②强烈的各向异性.③随着PT含量的增加,系统的弛豫行为逐渐减弱,在~0.33时,材料在室温下成为正常铁电体,但PE-FE相变并非正常铁电相变,表现为在时; ε~关系不遵守居里-外斯定律,而是遵守Smolenskii的关系.该相变也明显地与弥散相变不同.这种行为可用无规场的观点加以解释. 对PMN-PT陶瓷,其压电性能与最好的软性PZT相似,而ε和31略大.

关键词: 铌镁酸铅, 钛酸铅, 压电性, 相变

Abstract: Some special features in dielectric, piezoelectric properties and phase transition behavior of (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO_3 (PMN-PT) (x=0.24, 0.3, 0.33 and 0.35)
single crystals grown by Bridgman method were outlined: 1) Extremely high piezoelectric constant d33 (up to 3000 pC/N) and
coupling factors k33 and kt (up to 0.94 and 0.62 respectively), low mechanical factor of merit (Qm~60), large dielectric constant
ε(~5000). 2) Strong orientation dependence of piezoelectric properties. 3) with increasing PT content, the system becomes less relaxational,
but at least upto x=0.35, the system still partly exhibites relaxor feature: for x=0.33 and 0.35. ε~T curves look sharp enough to show
a normal ferroelectric like feature, however when T>Tm the ε~T relation does not obey Curie-Weiss law, but follows Smolenskii’s relation.
The piezoelectric properties of PMN-PT ceramics are similar to PZT-5H, but with higher ε and k31.

Key words: Pb(Mg1/3Nb2/3)O3-PbTiO3, piezoelectric property, relaxor

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