Universal exchange-driven phonon splitting in antiferromagnets.
Universal exchange-driven phonon splitting in antiferromagnets.
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反铁磁体中普遍交换驱动的声子分裂
DOI：
10.1103/physrevlett.108.177203
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发表时间：
2012
影响因子：
8.6
通讯作者：
A. Loidl
中科院分区：
文献类型：
--
作者：
Ch. Kant;M. Schmidt;Zhe Wang;F. Mayr;V. Tsurkan;J. Deisenhofer;A. Loidl
我们报道了反铁磁过渡金属一氧化物MnO、FeO、CoO、NiO和阻挫反铁磁氧化物尖晶石、和中的声子分裂与非主交换耦合常数的线性关系。它直接证实了<?format ?>的理论预测的交换诱导分裂的带中心光学声子的一氧化物，并解释了声子分裂的幅度和改变的符号上的非主导交换的符号也在阻挫氧化物尖晶石。实验发现的线性关系描述了这两个系统的分裂，并同意在反铁磁和钙钛矿结构的观察，可以忽略不计<?format ?>次近邻耦合发现非常不同的立方反铁磁体类的共同行为表明，在反铁磁过渡的非主导交换耦合的交换诱导声子分裂的普遍依赖。
We report a linear dependence of the phonon splittingon the nondominant exchange coupling constantin the antiferromagnetic transition-metal monoxides MnO, FeO, CoO, NiO, and in the frustrated antiferromagnetic oxide spinels,, and. It directly confirms <?format ?>the theoretical prediction of an exchange-induced splitting of the zone-center optical phonon for the monoxides and explains the magnitude and the change of sign of the phonon splitting on changing the sign of the nondominant exchange also in the frustrated oxide spinels. The experimentally found linear relationwith slopedescribes the splitting for both systems and agrees with the observations in the antiferromagnetsandwith perovskite structure and negligible <?format ?>next-nearest neighbor coupling. The common behavior found for very different classes of cubic antiferromagnets suggests a universal dependence of the exchange-induced phonon splitting at the antiferromagnetic transition on the nondominant exchange coupling.