Orbital-spin-coupled fluctuations in spinel vanadates MnV_2O_4
Orbital-spin-coupled fluctuations in spinel vanadates MnV_2O_4
复制标题
尖晶石钒酸盐 MnV_2O_4 的轨道自旋耦合涨落
DOI：
10.1103/physrevb.87.085111
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发表时间：
2013
影响因子：
3.7
通讯作者：
T. Arima
中科院分区：
文献类型：
--
作者：
Y. Nii. N. Abe;T. Arima
采用超声脉冲回波测量方法研究了V（）位上具有三简并轨道自由度的尖晶石钒酸盐mnvo的弹性特性。当温度接近从高温无序立方相到低温有序四方相的一阶转变时，剪切弹性常数明显软化。这种软化归因于两者之间的波动。此外，发现弹性异常对外部磁场敏感，揭示了自旋和轨道波动之间的耦合。利用朗道理论对弹性异常进行了较好的再现，说明了MnVO中的一种特征性前兆现象。
The elastic properties of a spinel vanadate MnVOthat has an orbital degree of freedom in the triply degenerateorbital at V() sites are investigated by ultrasonic pulse-echo measurement. Considerable softening of the shear elastic constantis observed as the temperature approaches the first-order transition from the high-temperature orbital-disordered cubic phase to the low-temperature orbital-ordered tetragonal phase. The softening is attributed to fluctuations betweenand. Moreover, the elastic anomaly is found to be sensitive to the external magnetic field, revealing a coupling between spin and orbital fluctuations. The elastic anomaly is well reproduced theoretically based on Landau theory and elucidates a characteristic precursor phenomenon in MnVO.