铜铽合金薄膜中的巨自旋霍尔效应

Giant Spin Hall Effect in Cu-Tb Alloy Thin Films.

作者信息

Xu Zhan, Hwee Wong Grayson Dao, Tang Jiaxuan, Liu Er, Gan Weiliang, Xu Feng, Lew Wen Siang

机构信息

School of Physical and Mathematical Sciences, Nanyang Technological University, 21 Nanyang Link, Singapore 637371, Singapore.

MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials Technology, School of Materials Science and Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.

出版信息

ACS Appl Mater Interfaces. 2020 Jul 22;12(29):32898-32904. doi: 10.1021/acsami.0c07441. Epub 2020 Jul 13.

DOI:10.1021/acsami.0c07441

PMID:32608235

Abstract

We report the giant spin current generation in CuTb alloys arising from the spin Hall effect. The maximum spin Hall angle from our CuTb-based magnetic heterostructures was found to be -0.35 ± 0.02 for CuTb. We find that the contribution of skew scattering is larger than the side jump for lower Tb concentrations (<14.9%), while the converse is true for higher Tb concentrations. Additionally, we also studied the Gilbert damping parameter, spin diffusion length, and spin-mixing conductance. Interfacial spin transparency was found to be 0.55 ± 0.03 for the CoFeB/CuTb interface. The spin diffusion length and spin-mixing conductance of the CuTb alloy are λ = 2.5 ± 0.3 nm and = (24.2 ± 1.0) × 10 cm, respectively. Our results pave a way for rare-earth metals to be used as a spin Hall material in highly efficient SOT devices.

摘要

我们报道了由自旋霍尔效应引起的CuTb合金中的巨自旋流产生。基于CuTb的磁性异质结构的最大自旋霍尔角对于CuTb而言为-0.35±0.02。我们发现，对于较低的Tb浓度（<14.9%），斜散射的贡献大于侧跳，而对于较高的Tb浓度则相反。此外，我们还研究了吉尔伯特阻尼参数、自旋扩散长度和自旋混合电导。发现CoFeB/CuTb界面的界面自旋透明度为0.55±0.03。CuTb合金的自旋扩散长度和自旋混合电导分别为λ = 2.5±0.3 nm和 = (24.2±1.0)×10 cm。我们的结果为稀土金属在高效自旋轨道矩器件中用作自旋霍尔材料铺平了道路。