中国物理B ›› 2022, Vol. 31 ›› Issue (8): 87503-087503.doi: 10.1088/1674-1056/ac673c

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Exchange-coupling-induced fourfold magnetic anisotropy in CoFeB/FeRh bilayer grown on SrTiO3(001)

Qingrong Shao(邵倾蓉)1, Jing Meng(孟婧)1, Xiaoyan Zhu(朱晓艳)1, Yali Xie(谢亚丽)2, Wenjuan Cheng(程文娟)1, Dongmei Jiang(蒋冬梅)1, Yang Xu(徐杨)1, Tian Shang(商恬)1, and Qingfeng Zhan(詹清峰)1,†   

  1. 1 Key Laboratory of Polar Materials and Devices(MOE), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China;
    2 Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
  • 收稿日期:2022-02-22 修回日期:2022-04-05 接受日期:2022-04-14 出版日期:2022-07-18 发布日期:2022-07-29
  • 通讯作者: Qingfeng Zhan E-mail:qfzhan@phy.ecnu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11874150, 51871233, and 12174103) and the Natural Science Foundation of Shanghai (Grant Nos. 21ZR1420500 and 21JC1402300).

Exchange-coupling-induced fourfold magnetic anisotropy in CoFeB/FeRh bilayer grown on SrTiO3(001)

Qingrong Shao(邵倾蓉)1, Jing Meng(孟婧)1, Xiaoyan Zhu(朱晓艳)1, Yali Xie(谢亚丽)2, Wenjuan Cheng(程文娟)1, Dongmei Jiang(蒋冬梅)1, Yang Xu(徐杨)1, Tian Shang(商恬)1, and Qingfeng Zhan(詹清峰)1,†   

  1. 1 Key Laboratory of Polar Materials and Devices(MOE), School of Physics and Electronic Science, East China Normal University, Shanghai 200241, China;
    2 Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China
  • Received:2022-02-22 Revised:2022-04-05 Accepted:2022-04-14 Online:2022-07-18 Published:2022-07-29
  • Contact: Qingfeng Zhan E-mail:qfzhan@phy.ecnu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11874150, 51871233, and 12174103) and the Natural Science Foundation of Shanghai (Grant Nos. 21ZR1420500 and 21JC1402300).

摘要: Exchange coupling across the interface between a ferromagnetic (FM) layer and an antiferromagnetic (AFM) or another FM layer may induce a unidirectional magnetic anisotropy and/or a uniaxial magnetic anisotropy, which has been extensively studied due to the important application in magnetic materials and devices. In this work, we observed a fourfold magnetic anisotropy in amorphous CoFeB layer when exchange coupling to an adjacent FeRh layer which is epitaxially grown on an SrTiO3(001) substrate. As the temperature rises from 300 K to 400 K, FeRh film undergoes a phase transition from AFM to FM phase, the induced fourfold magnetic anisotropy in the CoFeB layer switches the orientation from the FeRh$\langle 110\rangle $ to FeRh$\langle 100\rangle $ directions and the strength is obviously reduced. In addition, the effective magnetic damping as well as the two-magnon scattering of the CoFeB/FeRh bilayer also remarkably increase with the occurrence of magnetic phase transition of FeRh. No exchange bias is observed in the bilayer even when FeRh is in the nominal AFM state, which is probably because the residual FM FeRh moments located at the interface can well separate the exchange coupling between the below pinned FeRh moments and the CoFeB moments.

关键词: magnetic anisotropy, phase transition, CoFeB/FeRh, exchange coupling

Abstract: Exchange coupling across the interface between a ferromagnetic (FM) layer and an antiferromagnetic (AFM) or another FM layer may induce a unidirectional magnetic anisotropy and/or a uniaxial magnetic anisotropy, which has been extensively studied due to the important application in magnetic materials and devices. In this work, we observed a fourfold magnetic anisotropy in amorphous CoFeB layer when exchange coupling to an adjacent FeRh layer which is epitaxially grown on an SrTiO3(001) substrate. As the temperature rises from 300 K to 400 K, FeRh film undergoes a phase transition from AFM to FM phase, the induced fourfold magnetic anisotropy in the CoFeB layer switches the orientation from the FeRh$\langle 110\rangle $ to FeRh$\langle 100\rangle $ directions and the strength is obviously reduced. In addition, the effective magnetic damping as well as the two-magnon scattering of the CoFeB/FeRh bilayer also remarkably increase with the occurrence of magnetic phase transition of FeRh. No exchange bias is observed in the bilayer even when FeRh is in the nominal AFM state, which is probably because the residual FM FeRh moments located at the interface can well separate the exchange coupling between the below pinned FeRh moments and the CoFeB moments.

Key words: magnetic anisotropy, phase transition, CoFeB/FeRh, exchange coupling

中图分类号:  (Magnetic anisotropy)

  • 75.30.Gw
75.50.Ee (Antiferromagnetics) 75.50.Gg (Ferrimagnetics) 75.60.Nt (Magnetic annealing and temperature-hysteresis effects)