R&D: Magnetic Properties and Microstructures of Multi-Component Sm–Co-Based Films Prepared by High-throughput Experiments

Rare Metals has published an article written by Xin-Rui Zheng, Si-Zhe Liang, Zhao-Guo Qiu, Yan-Song Gong, Hong-Xia Meng, Gang Wang, Zhi-Gang Zheng, School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640, China, and Zhongshan R&D Center for Materials Surface and Thin Films Technology of the South China University of Technology, Gent Materials Surface Technology (Guangdong) Co., Ltd., Zhongshan, 528437, China, Wei-Xing Xia, Laboratory of Rare-Earth Magnetic Functional Materials, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, 315201, China, De-Chang Zeng, School of Materials Science and Engineering, South China University of Technology, Guangzhou, 510640, China, and Zhongshan R&D Center for Materials Surface and Thin Films Technology of the South China University of Technology, Gent Materials Surface Technology (Guangdong) Co., Ltd., Zhongshan, 528437, China, and Ping Liu, Department of Physics, University of Texas at Arlington, Arlington, TX76019, USA.

Abstract: “Sm–Co-based films play an irreplaceable role in special applications due to their high curie temperature and magnetocrystalline anisotropic energy, especially in heat-assisted magnetic recording (HAMR), but the complex composition of Sm–Co phase and unclear synergistic coupling mechanisms of multi-elemental doping become the challenges to enhance the properties. In this work, a novel strategy combining magnetron sputtering and a high-throughput experiment method is applied to solve the above-mentioned problems. Fe/Cu co-doping highly increases the remanence while maintaining a coercivity larger than 26 kOe, leading to an enhancement of the magnetic energy product to 18.1 MGOe. X-ray diffraction (XRD) and high-resolution transmission electron microscope (HRTEM) reveals that SmCo₅ phase occupies the major fraction, with Co atoms partially substituted by Fe and Cu atoms. In situ Lorentz transmission electron microscopy (LTEM) observations show that the Sm (Co, Cu)₅ phase effectively prohibits domain wall motions, leading to an increase of coercivity (H_c). Fe doping increases the low saturation magnetization (M_s) and low remanence (M_r) due to the Fe atom having a higher saturation magnetic moment. The magnetization reversal behaviors are further verified by micromagnetic simulations. Our results suggest that Sm–Co-based films prepared via Fe/Cu co-doping could be a promising candidate for high-performed HAMR in the future.“