Ba-ferrite thin film rigid disk for high density perpendicular magnetic recording

A magnetoplumbite type of hexagonal Ba-ferrite films, whose c-axis of crystallites is well oriented perpendicularly to the film plane, have been prepared by means of a conventional rf diode sputtering system. Morphological and crystallographic characteristics of sputtered Ba-ferrite films depend strongly on preparation conditions such as the distance between target and substrate dT-Sand partial pressure of oxygen gas PO2during the deposition. Ba-ferrite films with smooth surface are prepared at the extended dT-Sin the region of low PO2. Read/write characteristics of Ba-ferrite thin film deposited on thermally oxidized silicon wafer with radius of two inches were evaluated with ring type head. Recording density D50of Ba-ferrite thin film rigid disk depends strongly on Δθ50. In this work, D50of 110 and 190 kfrpi for Δθ50of 4.8 and 2.8°, respectively, have been attained.