Phase transitions, electrical conductivity and chemical stability of BiFeO3 at high temperatures
Phase transitions, electrical conductivity and chemical stability of BiFeO3 at high temperatures
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DOI：
10.1016/j.jssc.2010.03.014
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发表时间：
2010-05
影响因子：
3.3
通讯作者：
S. Selbach;T. Tybell;M. Einarsrud;T. Grande
中科院分区：
文献类型：
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作者：
S. Selbach;T. Tybell;M. Einarsrud;T. Grande
报道了多铁性钙钛矿BiFeO3显示两个一级结构相变。通过量热法和示差法证明了在925±5°C下的结构相变是一级相变。电导率测量显示，高于925±5°C的高温相是半导体的，与最近的报告不一致。过渡体积的符号和大小反映了两个一阶相变之间电导率不连续性的符号和大小。研究表明，高氧分压可以稳定BiFeO 3的包晶分解。最后，通常观察到的分解BiFeO 3在高温下的起源进行了讨论。
The multiferroic perovskite BiFeO3is reported to display two first order structural phase transitions. The structural phase transition at 925±5°C is demonstrated to be first order by calorimetry and dilatometry. Electrical conductivity measurements revealed that the high temperature phase above 925±5°C is semiconducting, in disagreement with recent reports. The sign and magnitude of the volumes of transition reflect the sign and magnitude of the discontinuities in electrical conductivity across the two first order phase transitions. A high partial pressure of oxygen was demonstrated to stabilise BiFeO3towards peritectic decomposition. Finally, the origins of the commonly observed decomposition of BiFeO3at high temperatures are discussed.