The effect of oxygen deficiency on the structural phase transition and electronic and magnetic properties of the spinel
The effect of oxygen deficiency on the structural phase transition and electronic and magnetic properties of the spinel
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缺氧对尖晶石结构相变及电磁性能的影响
DOI：
10.1088/0953-8984/9/8/006
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发表时间：
1997
期刊：
影响因子：
--
通讯作者：
N. Kamegashira
中科院分区：
文献类型：
--
作者：
J. Sugiyama;T. Atsumi;A. Koiwai;T. Sasaki;T. Hioki;S. Noda;N. Kamegashira
通过差示扫描量热法（DSC）、磁化率、核磁共振（NMR）和电阻率等测试手段，研究了氧的缺乏对尖晶石从立方相到四方相相变的影响。根据DSC测量，化学计量化合物的转变温度被确定为K。当从0增加到0.066时，发现的幅度减小约4 K;然后，幅度增加约41 K，进一步增加高达0.10;因此，曲线在约处呈现出宽的最小值。通过NMR和的测量也观察到和之间的这种关系。上的依赖性被认为是Mn离子的平均价态的减少和Mn离子之间的最近邻相互作用的稀释之间的竞争的结果。这两种效应都是由缺氧引起的;前者使缺氧升高，而后者使缺氧降低。
The effect of oxygen deficiency on a phase transition from cubic to tetragonal phase has been investigated for the spinels with by measurements of differential scanning calorimetry (DSC), magnetic susceptibility nuclear magnetic resonance ( NMR) and electronic resistivity . According to the DSC measurements, the transition temperature for a stoichiometric compound is determined to be K. As increases from zero to 0.066, the magnitude of is found to decrease by about 4 K; then, the magnitude of increases by about 41 K with further increase of up to 0.10; thus, the curve exhibits a broad minimum at around . This relationship between and is also observed by the measurements of NMR and . The dependence of on is considered to be a result of a competition between a decrease in the average valence of Mn ions and a dilution of the nearest-neighbour interaction between Mn ions. Both effects are caused by the oxygen deficiency; the former raises , whereas the latter reduces it.