NBT-KBT-LBT系无铅陶瓷的弛豫相变与介电性能研究  

Dielectric property and relaxor phase transition of NBT-KBT-LBT ceramics

作　　者：王瑾[1] 杜慧玲[1] 张盼 杜娴[1] 赵岑[1] 

机构地区：[1]西安科技大学材料科学与工程学院,西安710054

出　　处：《功能材料》2014年第2期30-34,共5页Journal of Functional Materials

基　　金：国家自然科学基金重点资助项目(51072162);教育部新世纪优秀人才基金资助项目(NCET-11-1044);陕西省国际合作资助项目(2012KW-10)

摘　　要：采用传统电子陶瓷制备工艺获得无铅压电陶瓷(1-x)(0.8Na0.5Bi0.5TiO3-0.2K0.5Bi0.5TiO3)-xLi0.5Bi0.5TiO3(NBT-KBT-xLBT),研究了该材料的相结构、介电、铁电及压电性能。结果表明,NBTKBT中引入LBT形成了单相钙钛矿固溶体,LBT的引入量为0.08≤x≤0.10时,该体系处于准同型相界处;随着LBT的引入量增加,陶瓷的烧结温度显著降低,介电温度异常峰对应的退极化温度Tf向高温方向移动,而铁电-顺电相变峰Tm则向低温方向移动,弛豫铁电相变特征也表现得更为明显,对弛豫相变与A位离子的局域分布不均匀及其在原子尺度上的有序无序排布之间的关联进行了初步探讨;在NBT-KBT体系中引入LBT有助于改善其铁电性能,提高压电活性,矫顽场Ec从14.5kV/cm(x=0.06)降低至12.3kV/cm(x=0.12),在准同型相界处(x=0.10),压电常数d33达到了145pC/N。LBT组分引入到NBT-KBT体系中可获得高压电常数及低矫顽场的无铅压电材料。（1-x）（0.8Na0.5 Bi0.5 TiO3-0.2K0.5 Bi0.5 TiO3 ）-xLi0.5Bi0.5TiO3 （NBT-KBT-xLBT）lead-free piezo-e-lectric ceramics were prepared by the conventional ceramic preparation method.Crystal structure,dielectric, ferroelectric and piezoelectric properties of the ceramics were investigated.According to XRD patterns,the morphotropic boundary lies in the composition range of 0.08≤x≤0.10.The temperature dielectric anomalous peak Tf which was corresponding to the depolarization temperature towards to higher temperature while the fer-roelectric-paraelectric phase transition peak Tm shift towards to lower temperature.Relaxor phase transition characteristics become stronger.The relationship between relaxation phase transition characteristics and A-site local structure are further discussed based on inhomogeneous distribution and disorder range in atomic scale. The ferroelectric properties of the NBT-KBT ceramics are further improved with the introduction of the LBT content.And the coercive field Ec decreases from 14.5 kV/cm （x=0.06）to 12.3 kV/cm （x=0.12）.The pie-zoelectric activity was enhanced with an increase in LBT content and piezoelectric constant d33 reaches 145 pC/N at the morphotropic phase boundary（x=0.10）.The lower sintering temperature,higher d33 and lower Ec value for NBT-KBT system could be obtained by the LBT incorporation.

关 键 词：钛酸铋钠 准同型相界 介电弛豫 压电性能 

分 类 号：TM223[一般工业技术—材料科学与工程]