Surface acoustic attenuation due to surface spin wave in ferro‐ and antiferromagnets
Surface acoustic attenuation due to surface spin wave in ferro‐ and antiferromagnets
复制标题
铁磁体和反铁磁体中的表面自旋波导致的表面声衰减
DOI：
10.1063/1.30437
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发表时间：
2008
期刊：
影响因子：
--
通讯作者：
M. Tachiki
中科院分区：
文献类型：
--
作者：
S. Maekawa;M. Tachiki
尽管有许多关于表面磁振子有趣性质的理论预测，但由于表面与体积之比很小，并且只有磁共振方法可用，观测受到了严重限制。在本文中，我们从理论上提出一种表面声波衰减技术，用于观测波数与声波相等的表面磁振子。表面声波使表面附近的晶格产生旋转运动，并引起磁各向异性轴的局部偏离。尽管在自由表面导致通常体磁振子激发的剪切应变消失，但这种在各向异性磁体中的旋转运动产生的效果与磁共振方法中旋转磁场的效果相同。因此，表面声波能够激发表面磁振子。例如，展示了如何通过使用……在MnF₂中轻松观测到米尔斯和萨斯洛提出的表面自旋反转不稳定性。
In spite of a number of theoretical predictions of interesting properties of surface magnons, observations have been severely restricted because of the smallness of the surface‐to‐volume ratio and the fact that only the magnetic resonance method has been available. In this paper, we propose theoretically a surface‐acoutic‐wave attenuation technique to observe a surface magnon with wave number equal to that of the acoustic wave. The surface acoustic wave gives a rotational motion to the lattice near the surface and induces a local deviation of the axis of magnetic anisotropy. Although shear strains responsible for the usual bulk magnon excitation vanish at the free surface, this rotational motion in anisotropic magnetic leads to the same effect as that of the rotating magnetic field in the magnetic resonance method. Thus, the surface acoustic wave can excite a surface magnon. As an example, it it shown how a surface spin‐flop instability proposed by Mills and Saslow may be easily observed in MnF2 by using ...