Improved magnetic anisotropy of Co‐based multilayer film with nitrogen dopant

作者：Ling-Ran Yu, Xiu-Lan Xu, Yi-ran Jia, Xuan Geng, Xujie Ma, Yifei Ma, Yong-Hui Zan, Chun Feng, Jiao Teng · 发表于：Rare Metals · 年份：2021 · DOI：10.1007/s12598-021-01732-1 · 被引用次数：8 · 研究领域：Magnetic properties of thin films、ZnO doping and properties、Magnetic and transport properties of perovskites and related materials

Abstract Modulating the magnetic anisotropy of ferromagnetic thin films is crucial for constructing high‐density and energy efficient magnetic memory devices. Ta/W(N)/Co/Pt multilayers were deposited on silicon substrates by magnetron sputtering at room temperature. The influences of N dopant on the magnetic anisotropy of the multilayers were investigated by preparing the sample with N incorporation. The results indicate that when sputtering W target with only argon gas (Ar), Ta/W/Co/Pt sample shows in‐plane magnetic anisotropy (IMA). When sputtering W target at a different amount of N 2 and Ar atmosphere, it can induce perpendicular magnetic anisotropy (PMA) for proper N‐doped Ta/W(N)/Co/Pt sample. When the gas flow ratio of Ar:N 2 is 16:6, the effective magnetic anisotropy constant reach its maximum value of 1.68 × 10 5 J·m −3 , which enhanced by about 400% than our past works (annealing treatment is necessary to induce PMA in Pt/Co/MgO system). X‐ray diffraction (XRD) and X‐ray reflection (XRR) results demonstrate that N dopants can effectively promote the formation of β‐W phase and reduce the roughness of W(N)/Co interface, which are beneficial for PMA. X‐ray electron spectroscopy (XPS) analysis reveals that N doping redistributes Co charges, nitrogen ions participate in electron allocation of Co and attract some electrons of Co to form orbital hybridization between Co 3d and N 2p. This may be another important reason for the PMA formation.