The Success of Fabrication of Pure SmFe2 Phase Film with Outstanding Perpendicular Magnetic Anisotropy

Shijie Liao; Fang Wang; Hui Shen; Jian Zhang

doi:10.3390/ma17092027

The Success of Fabrication of Pure SmFe₂ Phase Film with Outstanding Perpendicular Magnetic Anisotropy

Materials (Basel). 2024 Apr 26;17(9):2027. doi: 10.3390/ma17092027.

Authors

Shijie Liao^{1

2

3}, Fang Wang⁴, Hui Shen¹, Jian Zhang^{2

3}

Affiliations

¹ School of Materials Science and Engineering, Shanghai Institute of Technology, Shanghai 201418, China.
² CAS Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
³ Zhejiang Province Key Laboratory of Magnetic Materials and Application Technology, Ningbo Institute of Materials Technology and Engineering, Chinese Academy of Sciences, Ningbo 315201, China.
⁴ School of Materials and Chemical Engineering, Ningbo University of Technology, Ningbo 315211, China.

Abstract

This study used DC magnetron sputtering technology to fabricate Sm-Fe films and systematically investigated the phase transition behavior of Sm-Fe films with different Fe ratios. It was found that at higher Fe content, the films consisted of Sm₂Fe₁₇ or SmFe₇ phases; as Fe content decreased, the films were mainly composed of SmFe₃ or SmFe₂ phases; at higher Sm content, the films primarily consisted of Sm phase. Sm is prone to volatilization at high temperatures, so Ta was used as a capping layer to effectively suppress Sm volatilization, successfully synthesizing pure SmFe₂ phase films at a nearly 1:2 ratio. The magnetic properties and magnetostrictive behavior of the SmFe₂ films were investigated, revealing that pure-phase SmFe₂ films exhibit good perpendicular magnetic anisotropy and magnetostriction properties. The larger stress along the perpendicular-to-film direction, resulting from the absence of substrate-induced constraints, contributes to the excellent perpendicular magnetic anisotropy of the films. This study successfully synthesized pure-phase SmFe₂ films and discovered a new method for fabricating perpendicularly anisotropic films. The research findings are of great significance for the efficient synthesis of desired films with high phase formation temperatures containing volatile elements.

Keywords: SmFe2; magnetic films; perpendicular magnetic anisotropy.

Grants and funding

This work was supported by the National Key Research and Development Program of China No.2021YFB3500303 and 2023YFB3507001; National Natural Science Foundation of China No.51971234; NSAF Joint Fund of China No. U2130124.