Development of L10-ordered FePt Thin Film for Magnetic Recording Application

L1₀ FePt is a promising material candidate for heat assisted magnetic recording (HAMR) and spintronic device applications due to its superior physical properties, such as

excellent magneto-crystalline anisotropy, high saturation magnetization, good spin polarization efficiency, good chemical stability, etc. To control the long-range chemical

ordering (S), texture, magnetic properties, microstructure, and other physical properties such as Curie temperature (Tc) and anisotropy field (Hk) are the keys in developing

suitable nanostructured L10 FePt for different applications. Despite the significant research progresses in developing L1₀ FePt nanostructured thin film for HAMR media in

recent years, there are still many remaining challenges. This research aims at exploring for potential solutions and providing an alternative way of thinking to tackle these

challenges. One critical challenge related to developing L1₀ FePt for HAMR application is to control the texture of FePt nano-grains and reduce the number density of multi-variant FePt grains. Ideally, small perpendicularly ordered FePt grains with c-axis perpendicular to the film plane without c-axis distribution are desired. However, in reality, the presence of polycrystalline MgO underlayer grain boundaries, MgO (002) texture distribution, and its surface roughness will lead to FePt c-axis distribution and formation of multi-variant FePt grains. In this research, the effect of inserting an annealed Cr buffer layer beneath MgO underlayer and inserting a prefabricated MgO-C template layer on top of MgO underlayer on the texture and magnetic properties of FePt nano-grains are studied.