Sputter deposition and read/Write characteristics of Ba-ferrite thin film disk

Abstract

The nucleation mechanisms and the composition change in Ba ferrite films deposition by means of the Targets Facing Type of Sputtering system have been discussed in detail. In addition, an attempt to control their magnetic properties has been made and read/write characteristics of the films prepared on the disk substrates have been evaluated. The single phase Ba ferrite films composed of fine graines are deposited epitaxially on the c-axis well oriented ZnO layer even in the nucleation stage under a wide range of preparation conditions. Moreover, the film composition, the crystal structure and the magnetic properties depend strongly on oxygen partial pressure. The films sputtered from the targets of n=5 and 6 in the BaO.nFe203 system exhibit good crystallographic and magnetic properties under the wider range of sputtering conditions. The coercive force Hc can be decreased without increasing the critical temperature of c-axis orientation by substitution of In3+for Fe3+. Furthermore, the D50 increases and overwrite decreases with increase of In3+content. Consequently, high density perpendicular recording with D 50 of 88 kFRPI has been achieved by using a narrow gap (0.4 μm) ring head.