Multi-spin-state dynamics during insulator-metal crossover in LaCoO3
Multi-spin-state dynamics during insulator-metal crossover in LaCoO3
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DOI：
10.1103/physrevb.90.081109
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发表时间：
2014-08-18
影响因子：
3.7
通讯作者：
Tokura, Y.
中科院分区：
文献类型：
--
作者：
Doi, A.;Fujioka, J.;Tokura, Y.
用红外和非弹性x射线能谱研究了钙钛矿LaCoO_3通过光学声子的自旋态交叉(SSC)动力学。在热诱导SSC中，发现了与热激发自旋态耦合的反常无色散的Co-O键伸缩声子。由于热激活自旋态之间的强关联，增强的自旋态涨落与明显的电荷带隙无关，表明存在复杂的自旋态歧化，包括低、中、高自旋态。
We have investigated the dynamics of spin-state crossover (SSC) for perovskite LaCoO3 through optical phonons by means of infrared and inelastic x-ray spectroscopy. Upon thermally induced SSC, anomalously dispersionless Co-O bond stretching phonons coupled to the thermally excited spin state have been identified. The enhanced spin-state fluctuation irrespective of the presence of a clear charge gap suggests the emergence of complex spin-state disproportionation involving low-, intermediate-, and high-spin states due to the strong correlation among thermally activated spin states.