R&D: FePt Small-grain Film with Au Doping for High Density Perpendicular Magnetic Recording Media

Physica Scripta has published an article written by Li Zhang, Zhicheng Huang, Caiyan Liu, Xikun Lu, Che Xu, Guangxi Science and Technology Normal University, 966 Tiebei Ave., Laibin, Guangxi Zhuangzu Autonomous Region, 546199, China, and Chen Li, Yichun University, 576 Xuefu Rd., Yichun, Jiangxi, 336000, China.

Abstract: “In this study, we focused on a FePtAu-C small-grain film specifically designed for very-high density perpendicular magnetic recording media, surpassing 1Tbits/in² density. The film layer had a composition of Fe47Pt43Au10-C40% with 7.2 nm thickness. It was deposited onto a silicon substrate with one12nm thick magnesium oxide sandwich-layer at 560oC temperature. Notably, the film exhibited a perpendicular coercivity of 39 kOe. Based on transmission electron microscopy (TEM) analysis, the film small-grain size was determined to be approximately 8.2±1.6 nm. Furthermore, our investigation revealed that the grain size of magnesium oxide sandwich-layer was about 12 nm, which was larger than that of FePt. As a consequence, the FePt small-grains were not directly influenced by magnesium oxide small-grains beneath them. Moreover, a more in-depth examination using high-resolution TEM imaging demonstrated outstanding L10 ordering within the thin-film, corroborated by texture examination conducted via X-ray diffraction (XRD). It is noteworthy that magnesium oxide sandwich-layer exhibited a polycrystalline structure, while the FePt growing on top of magnesium oxide occurred in an epitaxial manner.“