Effect of Heat Treatment for Crystal Structure and Ferroelectric Properties of Sr1-xBi2+xTa2O9-δ (x=0, 0.2)
Effect of Heat Treatment for Crystal Structure and Ferroelectric Properties of Sr1-xBi2+xTa2O9-δ (x=0, 0.2)
复制标题
热处理对Sr1-xBi2+xTa2O9-δ (x=0, 0.2)晶体结构和铁电性能的影响
DOI：
10.2109/jcersj.110.859
复制
发表时间：
2002
影响因子：
1.1
通讯作者：
K. Takeuchi
中科院分区：
文献类型：
--
作者：
Y. Idemoto;Yuhei Sato;N. Koura;J. Richardson;C. Loong;K. Takeuchi
SrBi2Ta2O9铁电材料由(Bi2O2)2+层和钙钛矿块体(SrTa2O7)2-组成。热处理改变了晶体结构、缺陷、氧的非化学计量比和铁电性质。在本研究中，我们通过不同的热处理方法研究了Sr1-xBi2+xTa2O9-δ(x=0，0.2)的晶体结构、物理性能和铁电性能之间的关系。结果表明，当x=0时，样品的剩余极化(Pr)和矫顽场(EC)随热处理时间的延长而增大。在x=0.2时，随氧化方向的热处理，Pr几乎不变，Ec降低。X=0时，介电常数(ES)随氧化方向的热处理而增大，居里温度(T_C)随x=0时的热处理而降低。而当x=0.2时，Es随氧化方向的热处理而降低，而Tc随x=0.2的热处理而降低。根据Rietveld方法利用中子粉末衍射数据进行结构分析的结果表明，(Bi2O2)2+层和TaO4平面的变形以及TaO6八面体在a-c面上的倾斜角对EC有影响。TaO_6八面体在b-c面上的倾斜角影响T_c。
Ferroelectric material of SrBi2Ta2O9 consists of (Bi2O2)2+ layer and peseudoperovskite block, (SrTa2O7)2-. The crystal structure, defect, oxygen nonstoichiometory, and ferroelectric properties change by heat treatment. In this study, we investigated the relation between crystal structure, physical properties and ferroelectric properties by various heat treatment of Sr1-xBi2+xTa2O9-δ (x=0, 0.2). From the results, the remanent polarization (Pr) and coercive field (Ec) increase by heat treatment at x=0. On the other hand, Pr is almost constant and Ec decreased with heat treatment of oxidation direction at x=0.2. The dielectric constant (es) increase with heat treatment of oxidation direction and Curie temperature (Tc) decrease by heat treatment at x=0. On the other hand, es decreased with heat treatment of oxidation direction and Tc decrease by heat treatment at x=0.2. From the results of structural analysis by the Rietveld method using the neutron powder diffraction data, we concluded that the distortion of (Bi2O2)2+ layer and TaO4 plane, and tilting angle of TaO6 octahedra on a-c plane affect Ec. The tilting angle of TaO6 octahedra on b-c plane affects Tc.