Annealing influence on magnetic anisotropies of CoFe thin films

Weihua Zhu; Guanjie Wu; Hongwei Xue; Zhendong Zhu; Q. Y. Jin; Zongzhi Zhang

doi:10.1063/1.5079760

AIP Advances (Mar 2019)

Annealing influence on magnetic anisotropies of CoFe thin films

Weihua Zhu,
Guanjie Wu,
Hongwei Xue,
Zhendong Zhu,
Q. Y. Jin,
Zongzhi Zhang

Affiliations

Weihua Zhu: Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-Precision Optical Manufacturing Engineering Center, Fudan University, Shanghai 200433, China
Guanjie Wu: Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-Precision Optical Manufacturing Engineering Center, Fudan University, Shanghai 200433, China
Hongwei Xue: Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-Precision Optical Manufacturing Engineering Center, Fudan University, Shanghai 200433, China
Zhendong Zhu: Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-Precision Optical Manufacturing Engineering Center, Fudan University, Shanghai 200433, China
Q. Y. Jin: Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-Precision Optical Manufacturing Engineering Center, Fudan University, Shanghai 200433, China
Zongzhi Zhang: Department of Optical Science and Engineering, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), and Shanghai Ultra-Precision Optical Manufacturing Engineering Center, Fudan University, Shanghai 200433, China

DOI: https://doi.org/10.1063/1.5079760
Journal volume & issue: Vol. 9, no. 3
pp. 035305 – 035305-4

Abstract

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Post-annealing effect on the magnetic anisotropies of cubic CoFe films epitaxially grown on MgO (001) substrates are investigated. X-ray diffraction patterns reveal that the crystallization degree gradually improves with the increase of annealing temperature (Ta), which results in obvious enhancement in both the uniaxial (HU) and biaxial magnetic anisotropy fields. Magnetic hysteresis loops of the unannealed sample show two equivalent easy axes along the CoFe [110] and [11¯0] directions, being in accord with the observed fourfold symmetry of angular remanent magnetization (ARM) curve. Nevertheless, with the increase of Ta, the two easy axis loops become inequivalent due to the increased HU along [110] direction, thus giving rise to a two-step switching behavior for the [11¯0] direction loop at Ta>350°C and the ARM curve transformation from fourfold to twofold symmetry. This work provides a deep insight and an effective approach to control the magnetic anisotropies and magnetization states for practical applications.

Published in AIP Advances

ISSN: 2158-3226 (Online)
Publisher: AIP Publishing LLC
Country of publisher: United States
LCC subjects: Science: Physics
Website: http://aipadvances.aip.org/

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