Microstructure of stainless steel films utilizable for magnetic recording

Abstract

In this study the microstructure of vapor-quenched stainless steel films, which are utilizable for a new type of magnetic recording disks, was investigated. Nickel-enriched SUS304 stainless steel films have a moderate saturation magnetization of 500 emu cm −3 and a high coercivity of 200 Oe and are promising for use as a magnetic recording layer. These magnetic properties seem to originate from their unique microstructure. These vapor-quenched films have a very dense and fine morphology composed of magnetic grains of the b.c.c. or b.c.t. phases and nonmagnetic grains of the f.c.c. phase. Magnetic grains are isolated from each other by nonmagnetic layers not only in the directions parallel to the film plane but also normal to the film plane. The volume fraction of the magnetic grains determines their saturation magnetization and the pinning effect due to their microstructure may be the cause of high coercivity.