Photoinduced dynamics of sublattice magnetization in ferrimagnets:: FeCr2S4 and CoCr2S4
Photoinduced dynamics of sublattice magnetization in ferrimagnets:: FeCr2S4 and CoCr2S4
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DOI：
10.1143/jpsj.75.083707
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发表时间：
2006-08-01
影响因子：
1.7
通讯作者：
Tokura, Yoshinori
中科院分区：
文献类型：
--
作者：
Ogasawara, Takeshi;Ohgushi, Kenya;Tokura, Yoshinori
利用时间分辨磁光克尔光谱探测元素特异性光学跃迁，研究了铁磁性化合物FeCr2S4和CoCr2S4亚晶格磁化的光致动力学。在FeCr2S4中，观察到亚晶格磁化的非共线动力学。在200fs激光脉冲照射下，Cr亚晶格的磁化强度开始进动，而Fe亚晶格的磁化强度开始下降，但没有进动。相比之下，在CoCr2S4中，Co和Cr亚晶格矩表现出相同的进动，在光激发后保持共线关系。通用共线/非共线自旋动力学可以用Fe/Co位点磁晶各向异性与Cr和Fe/Co自旋之间交换相互作用的相对大小来解释。
The photoinduced dynamics of sublattice magnetization in ferrimagnetic compounds, FeCr2S4 and CoCr2S4, was investigated by time-resolved magneto-optical Kerr spectroscopy probing element-specific optical transitions. In FeCr2S4, the non-collinear dynamics of the sublattice magnetizations was observed. Upon irradiation of a 200fs laser pulse, the Cr sublattice, magnetization starts to precess, whereas the Fe sublattice magnetization starts to decrease without precession. In CoCr2S4, by contrast, Co and Cr sublattice moments show the same precession, retaining the collinear relation after photoexcitation. The versatile collinear/noncollinear spin dynamics can be accounted for in terms of the relative magnitude of the magnetocrystalline anisotropy at the Fe/Co site to the exchange interaction between Cr and Fe/Co spins.