Barium ferrite thin film for longitudinal recording

摘要

A high-density recording media comprising longitudinally oriented polycrystalline barium ferrite exhibits large coercivity, corrosion resistance, high hardness and durability. Films are prepared by on-axis sputtering at ambient temperatures from stoichiometric targets followed by a post-deposition anneal at approximately 850 DEG C. to induce crystallization. Crystallization yields a magnetic film with large in-plane remanence and a fine scale texturing that greatly improves the tribological performance of barium ferrite disks. Exceptional durability can be achieved on disks without overcoats. Grain sizes as small as 200 ANGSTROM are produced by doping with small amounts of Cr2O3 or other additives. Coercivities greater than 4000 Oe are achieved even in small grain films.