四方相区NBT-KBT无铅铁电介电弛豫与铁电相变研究  

Dielectric Relaxation and Ferroelectric Phase Transition of Tetragonal Structure NBT-KBT Lead-free Ferroelectricity

作　　者：李月明[1] 陈文[2] 徐庆[2] 江向平[1] 张玉平[1] 

机构地区：[1]景德镇陶瓷学院,景德镇333001 [2]武汉理工大学材料科学与工程学院,武汉430070

出　　处：《人工晶体学报》2006年第4期849-853,共5页Journal of Synthetic Crystals

基　　金：国家自然科学基金(No.50272044;50562002);日本NSG基金资助

摘　　要：本文研究了具有四方结构的(Na1-xKx)0.5B i0.5TiO3体系中x=0.22,0.26和0.30陶瓷材料不同温度下的电滞回线,结合变温XRD和介电温谱分析,发现该体系四方结构的组成为反铁电体,但紧靠准同型相界的四方结构由于场诱导下引起的反铁电-铁电相变,表现出铁电体特性,材料在升温过程中由于反铁电宏畴向微畴的转变导致了介电峰的产生,且在介电温谱上表现出强烈的介电常数-频率依赖性,为弛豫铁电体特征。In this paper, the hysteresis loops and XRD patterns at different temperatures as well as dielectric constant as a function of temperature for （Na（1-x）Kx）0.5Bi0.5TiO3（ x = 0.22,0.26, 0.30） ceramic composites composites with tetragonal symmetry structure were investigated. It is found that the tetragonal structure are anti-ferroelectric, but the composite near to the morphotropic phase boundary （MPB） showed ferroelectric characteristic because the anti-ferroelectric to ferroelectric phase transition was induced under electric field. The intense dependence of dielectric constant to frequency shows these materials are relaxor ferroelectric, and the appearance of the dielectric peak at heating process is caused by the transition of anti-ferroelectric macro-domain to micro-domain.

关 键 词：钛酸铋钠 钛酸铋钾 反铁电相变 介电弛豫 

分 类 号：TM282[一般工业技术—材料科学与工程]