0．94Na1／2Bi1／2TiO3-0．06BaTiO3无铅压电单晶的生长及电学性能研究  

Growth and Electrical Properties of 0.94Na_(1/2)Bi_(1/2)TiO_3-0.06BaTiO_3 Lead-free Piezoelectric Single Crystal

作　　者：刘洪[1] 葛文伟[2] 江向平[1] 赵祥永[2] 罗豪甦[2] 

机构地区：[1]景德镇陶瓷学院材料科学与工程系,景德镇333001 [2]中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室

出　　处：《人工晶体学报》2008年第4期881-885,共5页Journal of Synthetic Crystals

基　　金：国家自然科学基金(No.50562002,50602047);教育部新世纪优秀人才计划(NCET-06-0576);江西省自然科学基金(0650074,2007GZC1258);上海硅酸盐研究所高性能陶瓷国家重点实验室开放课题(SKL200610SIC)

摘　　要：采用坩埚下降法成功生长出尺寸达φ15mm×50mm的0．94Na1／2Bi1/2TiO3-06BaTiO3（NBBT94／6）无铅压电单晶。利用X射线荧光沿纵向对晶体棒成分分析表明：Na＋、Bi3＋、Ti3＋离子的含量沿纵向波动较小，而Ba2＋离子的含量却波动较大。XRD结构分析表明，晶体棒的中、下部分属于三方相钙钛矿结构，而上部转变为四方相钙钛矿结构。详细研究晶体棒中部0．952Na1/2Bi1/2TiO3-0．048BaTiO3（NBBT95．2／4．8）的介电及压电行为表明：非自发极化方向[001]、[110]样品的退极化温度乃分别为200℃和150℃，具有明显的结晶学方向依赖性，且在Td附近表现出典型的介电弛豫行为；在3～5kV／mm电压极化下，[001]、[110]方向样品的最大压电系数d33分别为165pC／N、110pC／N，机电耦合系数k1分别为49．8％、45．0％。Lead-free piezoelectric crystal of 0. 94Na1/2 Bi1/2 TiO3-0. 06BaTiO3 （ NBBT94/6 ） with a dimension of φ15 mm ×50 mm has been successfully grown by Bridgman technique. X-ray fluorescence analysis reveals that the concentrations of Na＋ , Bi3＋ and Ti4＋ vary slightly along the growth direction, while the concentration of Ba2＋ varies greatly. XRD shows that the grown crystals are of pure perovskite structure with a rhombohedral symmetry in the bottom and middle parts, while the upper part belongs to tetragonal symmetry. The dielectric and piezoelectric properties for 0. 952Na1/2Bi1/2TiO3-0. 048BaTiO3 （NBBT95.2/4.8） crystals were mainly investigated in detail. The results show that the [001 ], [ 110] samples possess relaxor dielectric behavior and Td of [001 ],[110] samples are 200℃, 150℃ respectively, obviously depending on crystallographic direction. Moreover, maximum d33 of 165 pC/N,110 pC/N and kt of 49.8% , 45.0% are obtained for the [001 ] , [ 110] samples poled under 3-5 kV/ mm, respectively.

关 键 词：钛酸铋钠 无铅 晶体生长 介电弛豫 压电性能 

分 类 号：O738[理学—晶体学]