Surface magnetization thermal fluctuation driven anomalous behaviour of ordinary Hall effect in Pt/YIG
Surface magnetization thermal fluctuation driven anomalous behaviour of ordinary Hall effect in Pt/YIG
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DOI：
10.1088/1361-6463/aaf6c3
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发表时间：
2018-12
期刊：
影响因子：
--
通讯作者：
L. Lang;Shiming Zhou;X. Qiu
中科院分区：
文献类型：
--
作者：
L. Lang;Shiming Zhou;X. Qiu
普通霍尔系数（OHC）表征了电子的扩散，因此是严格获得涉及强自旋轨道耦合的磁性异质结构中自旋扩散长度和自旋霍尔角的必要前提。在这里，OHC研究在Pt层与铁磁绝缘Y3 Fe 5 O 12膜接触。OHC是负的，异常地随着温度的升高而显著增加，而对于厚的Pt层，OHC的变化可以忽略不计。在顺磁Gd_3Ga_5O_（12）衬底上的等电子和铁磁Ni薄膜中也观察到类似的反常现象。然而，对于Gd_3Ga_5 O_（12）衬底上的Pt膜，OHC总是随着温度的升高而减小。自旋极化Pt/Y3 Fe 5 O 12和铁磁Ni薄膜中OHC的反常行为被认为是由于磁性邻近和表面磁化热涨落的综合作用导致费米能级和费米面形状的显著变化。本文的工作将有助于理解Pt层中纯自旋电流的弛豫机制。
The ordinary Hall coefficient (OHC) characterizes the electron diffusion and therefore is the essential prerequisite for rigorously acquiring the spin diffusion length and spin Hall angle in magnetic heterostructures that involves strong spin–orbit coupling. Here, OHC is investigated in Pt layers in contact with ferromagnetic insulating Y3Fe5O12 films. The OHC, being negative, abnormally increases in magnitude significantly with increasing temperature for ultrathin Pt layers whereas it shows negligible change for thick ones. Similar anomalous phenomena are observed for isoelectronic and ferromagnetic Ni films on paramagnetic Gd3Ga5O12 substrates. For Pt films on Gd3Ga5O12 substrates, however, the OHC always decreases in magnitude with increasing temperature. The anomalous behaviour of OHC in spin polarized Pt on Y3Fe5O12 and ferromagnetic Ni films is suggested to arise from significant changes of the Fermi level and the Fermi surface shape through combined effects of the magnetic proximity and the surface magnetization thermal fluctuation. The present work will facilitate the understanding of relaxation mechanism of pure spin current in Pt layers.