La掺杂SrBi_4Ti_4O_(15)铁电材料性能研究  

Study of properties of lanthanum doped SrBi_4Ti_4O_(15) ferroelectric ceramics

作　　者：朱骏[1] 卢网平[1] 刘秋朝[1] 毛翔宇[1] 惠荣[1] 陈小兵[1] 

机构地区：[1]扬州大学物理科学与技术学院,扬州225002

出　　处：《物理学报》2003年第6期1524-1528,共5页Acta Physica Sinica

基　　金：江苏省教育厅自然科学基金 (批准号 :0 1KJB14 0 0 11)资助的课题~~

摘　　要：按x=0 0 0 ,0 10 ,0 2 5 ,0 5 0 ,0 75和 1 0 0 ,采用固相烧结工艺 ,制备了不同La掺杂量的SrBi4-xLaxTi4O1 5的陶瓷样品 .用x射线衍射对其微结构进行了分析 ,并测量了铁电、介电性能 .结果发现 ,La掺杂未改变SrBi4Ti4O1 5的晶体结构 .随掺杂量的增加 ,样品的矫顽场 (Ec)下降 ,剩余极化 ( 2Pr)先增大 ,后减小 .在x =0 2 5时 ,2Pr 达到极大值 ,为2 4 2 μC·cm- 2 ,这时Ec=60 8kV·cm- 1 ,与SrBi4Ti4O1 5相比 ,2Pr 增加了近 5 0 % ,而Ec 下降了近 2 5 % ,材料铁电性能显著提高 .SrBi4-xLaxTi4O1 5的相变温度Tc 随x的增加逐渐降低 ,x =0 2 5时 ,Tc=45 1℃ .在x =0 75 ,1 0 0时 。Ceramic samples SrBi4-xLaxTi4O15 (x = 0.00, 0.10, 0.25, 0.50, 0.75, 1.00), have been prepared by solid-state reaction method. Their structure was analyzed by x-ray diffraction, and their dielectricity and ferroelectricity were measured. It is found that La-doping does not change the crystal structure of SrBi4Ti4O15. The remnant polarization (2P(r)) increases at first, then decreases with the increase of La content. The 2P(r) reaches a maximum value of 24.2 muC.cm(-2), when x is 0.25. The coercive field of SrBi3.75La0.25Ti4O15 is 60.8 kV.cm(-1). The 2P(r) increases by about 50% and the E-c decreases near 25%, compared with these of SrBi4Ti4O15. Obviously, the ferroelectricity of SrBi4Ti4O15 is improved by lanthanum doping. The temperature of phase transition (T-c) decreased with La cloping. The T-c of SrBi3.75La0.25Ti4O15 is 451 degreesC. When x = 0.75 and 1.00, the SrBi4-xLaxTi4O15 exhibit the typical characteristics of relaxor ferroelectrics.

关 键 词：LA掺杂 镧掺杂 铁电材料 相变温度 弛豫铁电 铁电随机存储器 介电性能 SRBI4TI4O15 微结构 

分 类 号：O482.4[理学—固体物理]