Synthesis, structure and characterisation of the n=4 Aurivillius phase Bi5Ti3CrO15
Synthesis, structure and characterisation of the n=4 Aurivillius phase Bi5Ti3CrO15
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DOI：
10.1016/j.jssc.2010.09.031
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发表时间：
2011-02-01
影响因子：
3.3
通讯作者：
Hyatt, N. C.
中科院分区：
文献类型：
--
作者：
Giddings, A. T.;Stennett, M. C.;Hyatt, N. C.
用固相反应合成了n=4的Aurivillius相Bi5Ti3CrO15。高分辨中子衍射数据的Rietveld分析表明，该材料在室温下采用极性空间群A2(1)Am，在650℃以上转变为星型I4/mmm结构。这一相变与DSC信号和相对介电常数的反常相一致，这是铁电-顺电相变的特征。Bi5Ti3CrO15在低温下表现出顺磁行为，具有短程反铁磁相互作用，但没有证据表明长程磁有序。这被认为是钛和铬在可用的八面体位置上严重无序的结果，正如对中子衍射数据的分析所证明的那样。(C)2010 Elsevier Inc.保留所有权利。
The n=4 Aurivillius phase, Bi5Ti3CrO15, was synthesised by solid state reaction. Rietveld analysis of high resolution neutron diffraction data demonstrated this material to adopt the polar space group A2(1)am at room temperature, transforming to the aristotype I4/mmm structure above 650 degrees C. This phase transition is coincident with an anomaly in DSC signal and relative permittivity, which are characteristic of a ferroelectric-paraelectric phase transition. Bi5Ti3CrO15 exhibits paramagnetic behaviour at low temperature, with short range antiferromagnetic interactions, but no evidence for long range magnetic ordering. This is considered a consequence of significant disorder of Ti and Cr over the available octahedral sites, as demonstrated by analysis of neutron diffraction data. (C) 2010 Elsevier Inc. All rights reserved.