Sr位Nd掺杂对SrBi2Nb2O9性能的影响及机理研究  

Effects of substitutions of Nd^(3+) for Sr^(2+) on the properties of SrBi_2Nb_2O_9 ceramics and their mechanism

作　　者：孙琳[1] 褚君浩[1] 杨平雄[1] 冯楚德[2] 

机构地区：[1]华东师范大学信息科学技术学院,极化材料与器件教育部重点实验室,上海200241 [2]中国科学院上海硅酸盐研究所,上海200050

出　　处：《物理学报》2009年第8期5790-5797,共8页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(批准号:2007CB924901);国家自然科学基金(批准号:60677022);上海市科学技术委员会基础研究重点项目(批准号:07DZ22943,08JC1409000)资助的课题~~

摘　　要：采用传统固相法制备了(Sr1-3x/2Ax/2Ndx)Bi2Nb2O9(x=0,0.05,0.1和0.2)陶瓷,并系统研究了Nd离子取代Sr离子对SrBi2Nb2O9性能的影响及其作用机理.研究结果表明:Sr1-3x/2Ax/2NdxBi2Nb2O9的介电常数和介电损耗随温度变化的行为具有明显的离子松弛极化特征.Nd3+对Sr2+的部分取代,导致Sr1-3x/2Ax/2NdxBi2Nb2O9剩余极化强度Pr稍有下降,但其压电系数d33却有所增加,根据铁电热力学理论,这是Nd3+对Sr2+取代导致材料介电常数增大所致.Sr1-3x/2Ax/2NdxBi2Nb2O9的居里温度(TC)没有随Nd含量的增加而变化,拉曼光谱技术分析表明这是其NbO6八面体畸变程度没有发生变化所致.Nd3+取代Sr2+提高了材料的介电常数εr、压电系数d33、机电耦合系数Kp,同时降低了机械品质因数Q,但是谐振频率温度系数C值没有改变.（ Sr1- 3x/2 Ax/2 Ndx ） Bi2 Nb2O9 （ x = 0,0.05,0.1 and 0.2） ceramics are prepared by traditional solid-reaction method, and effects of substitutions of Nd3＋ for Sr2＋ on the properties of SrBi2 Nb209 ceramics and their mechanism are investigated. The results show that the temperature spectra of dielectric constant and loss for these Nd-doped samples are obviously characteristic of ion relaxor polarization. The partial substitution of Nd3＋ for Sr2＋ leads to the slight reduction in remanent polarization （Pr） and the increase in piezoelectric coefficient d33 , which can be attributed to the increase in dielectric constant of samples according to ferroelectric thermodynamics theory. Raman spectrum shows that no change in the Curie temperature （ Tc ） of （Sr1 3x/2 AxlE Ndx ） Bi2 Nb2O9 samples is observed, which might result from no appreciable variation in NbO6 octahedron distortion. For （Sr1-3x/2 Ax/2 Ndx） Bi2Nb209 ceramics, the substitution of Nd3＋ for Sr2＋ increases permittivity er, piezoelectric coefficient d33, and electromechanical coupling coefficient Kp and reduces mechanical quality factor Qm, but it does not change temperature coefficient of harmonic frequency value.

关 键 词：压电陶瓷 介电性能 压电性能 拉曼光谱 

分 类 号：O483[理学—固体物理]