PRESSURE-INDUCED INTERMEDIATE-TO-LOW SPIN STATE TRANSITION IN LACOO3
PRESSURE-INDUCED INTERMEDIATE-TO-LOW SPIN STATE TRANSITION IN LACOO3
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DOI：
10.1103/physrevb.67.140401
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发表时间：
2002-10
影响因子：
3.7
通讯作者：
T. Vogt;J. Hriljac;N. Hyatt;P. Woodward
中科院分区：
文献类型：
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作者：
T. Vogt;J. Hriljac;N. Hyatt;P. Woodward
同步加速器x射线粉末衍射实验表明，lacoo3从磁性中间自旋态（IS）到非磁性低自旋基态（62g）的转变通常在冷却时观察到，在压力下表现为异常低的150(2)GPa的体积模量和最初非常大的Co-O键可压缩性4.8×10 - 3gpa - 1，在4 GPa附近趋于稳定。IS态的持续减少是由于晶体场分裂的增加导致Co 3 +阳离子尺寸的有效减小。
Synchrotron x-ray powder-diffraction experiments reveal that the transition from a magnetic intermediate spin (IS) state t 5 2ge 1 g to a nonmagnetic low-spin ground state t 6 2g in LaCoO 3 normally observed when cooling manifests itself under pressure by an anomalously low bulk modulus of 150(2) GPa and an initially very large Co-O bond compressibility of 4.8×10 - 3 GPa - 1 which levels off near 4 GPa. The continuous depopulation of the IS state is driven by an increased crystal-field splitting resulting in an effective reduction of the size of the Co 3 + cation.