Crystal phases and Yb valence transition in Ybx>In1−x>Cu2
Crystal phases and Yb valence transition in Ybx>In1−x>Cu2
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Ybx>In1−x>Cu2 中的晶相和 Yb 价态跃迁
DOI：
10.1016/0304-8853(89)90004-8
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发表时间：
1989
影响因子：
2.7
通讯作者：
T. Hihara
中科院分区：
文献类型：
--
作者：
K. Kojima;H. Hayashi;A. Minami;Y. Kasamatsu;T. Hihara
本文对Yb_xIn_（1-x）Cu_（2-x）（x = 0.4和0.5）进行了冶金学、晶体学和磁学研究。电子探针X射线显微分析表明，出现价态转变的相为YbInCu 4（x= 0.5），x = 0.4的样品主要为YbInCu 4和InCu 2两相。YbInCu_4的晶体结构属于C_（15）b型，Yb离子在晶体中是有序的。在良好的退火样品的磁化率行为的自由Yb 3+离子above Tv = 40 K，低于它几乎保持不变。在40 K时，随着温度的降低，115 In的Knight位移从-2.4%急剧变化到+0.2%。实验结果与低于Tv的双价涨落态的形成是一致的。
Metallurgical, crystallographic and magnetic investigations have been made in YbxIn1-xCu2withx= 0.4 and 0.5, which exhibits the temperature-induced Yb valence phase transition. Electron probe X-ray microanalysis reveals that the phase exhibiting the valence transition is YbInCu4(x= 0.5) and the sample ofx= 0.4 is primarily in the two phases of YbInCu4and InCu2. The crystal structure of YbInCu4is found to be of the C15b type one, in which Yb ions are ordered. In well-annealed samples the susceptibility behaves as that for the free Yb3+ion aboveTv= 40 K, below which it remains nearly constant. The115In Knight shift shows a drastic change from -2.4 to +0.2% at 40K with lowering the temperature. The experimental results are consistent with a formation of nonmagnetic valence fluctuating states belowTv.