Charge-spin interconversion in epitaxial Pt probed by spin-orbit torques in a magnetic insulator
Charge-spin interconversion in epitaxial Pt probed by spin-orbit torques in a magnetic insulator
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DOI：
10.1103/physrevmaterials.5.064404
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发表时间：
2021-06-04
影响因子：
3.4
通讯作者：
Emori, Satoru
中科院分区：
文献类型：
--
作者：
Li, Peng;Riddiford, Lauren J.;Emori, Satoru
我们在全外延铁氧体/Pt双层模型系统中测量了自旋轨道扭矩（SOT），以深入了解Pt中的电荷-自旋相互转换。由于绝缘铁氧体中的电子传导可以忽略不计，结晶Pt膜充当电荷到自旋转换的唯一来源。一个小的fieldlike SOT独立的Pt厚度表明在铁氧体/Pt界面的弱Rashba-Edelstein效应。相比之下，我们观察到一个相当大的dampinglike的SOT，取决于Pt的厚度，从中我们推断的显性的非本征自旋霍尔效应（斜散射）和Dyakonov-Perel自旋弛豫的结晶Pt膜。此外，我们的研究结果指出，一个大的内部自旋霍尔比约为0.8的外延铂。我们的实验工作朝着理解Pt基异质结构中的电荷-自旋相互转换和SOT的机制迈出了重要的一步，这对于高效自旋电子器件至关重要。
We measure spin-orbit torques (SOTs) in a model system of all-epitaxial ferrite/Pt bilayers to gain insights into charge-spin interconversion in Pt. With negligible electronic conduction in the insulating ferrite, the crystalline Pt film acts as the sole source of charge-to-spin conversion. A small fieldlike SOT independent of Pt thickness suggests a weak Rashba-Edelstein effect at the ferrite/Pt interface. By contrast, we observe a sizable dampinglike SOT that depends on the Pt thickness, from which we deduce the dominance of an extrinsic spin-Hall effect (skew scattering) and Dyakonov-Perel spin relaxation in the crystalline Pt film. Furthermore, our results point to a large internal spin-Hall ratio of approximate to 0.8 in epitaxial Pt. Our experimental work takes an essential step towards understanding the mechanisms of charge-spin interconversion and SOTs in Pt-based heterostructures, which are crucial for power-efficient spintronic devices.