Ferroelectric phase transitions in SrBi2Nb2O9 and Bi5Ti3FeO15: A powder neutron diffraction study
Ferroelectric phase transitions in SrBi2Nb2O9 and Bi5Ti3FeO15: A powder neutron diffraction study
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DOI：
10.1103/physrevb.67.092102
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发表时间：
2003-03
影响因子：
3.7
通讯作者：
A. Snedden;C. Hervoches;P. Lightfoot
中科院分区：
文献类型：
--
作者：
A. Snedden;C. Hervoches;P. Lightfoot
用粉末中子衍射研究了分别含有两层和四层钙钛矿结构的Aurivillius相铁电体SrBi 2Nb 2 O 9和Bi 5 Ti 3FeO 15的结构相变。在低于铁电居里温度的温度下，这两种材料在极性正交空间群A2 - 1 AM中结晶。在通过TC时，两相似乎直接转变为四电子顺电相，空间群为I4/mmm。该行为与类似物Sr 0的行为形成对比。8 5 Bi. 1 Ta 2 O 9和SrBi 4 Ti 4 O 1 5，这两种化合物都明确地显示出通过中间顺电正交相转变，空间群为Aamm。
Structural phase transitions in the Aurivillius phase ferroelectrics SrBi 2 Nb 2 O 9 and Bi 5 Ti 3 FeO 1 5 , containing two and four perovskite layers, respectively, have been studied using powder neutron diffraction. At temperatures below the ferroelectric Curie temperature both materials crystallize in the polar orthorhombic space group A2 1 am. On passing through T C , both phases appear to transform directly to a tetragonal paraelectric phase, space group I4/mmm. This behavior contrasts with that of the analogs Sr 0 . 8 5 Bi 2 . 1 Ta 2 O 9 and SrBi 4 Ti 4 O 1 5 , both of which have been shown unambiguously to transform via an intermediate paraelectric orthorhombic phase, space group Amam.