Extremely thin Sr-ferrite films with large perpendicular magnetic anisotropy prepared by facing targets sputtering with mixture gas of Ar and Kr

Summary form only given. In order to achieve high density and low noise recording performance in perpendicular magnetic recording media, extremely thin films, which consist of fine grains with high magnetic anisotropy energy are essentially required. Hexagonal ferrite thin films, such as Ba-ferrite (BaM), are regarded as one of the candidates for the perpendicular magnetic recording media. It is reported that BaM thin films with several nano-meter thicknesses could be deposited on the Pt[111] underlayer by facing targets sputtering (FTS) system, because of the suppression of radiation damage to the growing films by the high energy negative oxygen ions. However, perpendicular coercivity H/sub c/spl perp// of such a thin BaM films deteriorated for the thickness below 40 nm. Sr ferrite (SrM) is hopeful for its higher magneto-crystalline anisotropy constant than that of BaM. In this study, extremely thin Sr ferrite (SrM) layers with several nano-meter thickness were deposited on Pt[111] underlayer using facing targets sputtering apparatus without post-annealing. A mixture gas of Kr and Ar was effective to prepare extremely thin SrM films.