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.
出处
《人工晶体学报》
EI
CAS
CSCD
北大核心
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
关键词
钛酸铋钠
钛酸铋钾
反铁电相变
介电弛豫
sodium-bismuth titanate
potassium-bismuth titanate
anti-ferroelectric phase transition
dielectric relaxation
