Crystal orientation of Mn-Ir antiferromagnetic films for exchange-biased soft-magnetic underlayer in perpendicular recording media

Three kinds of crystal orientations for Mn-Ir antiferromagnetic films were successfully obtained on the glass disk substrates. Mn-Ir(111) film was prepared on an underlayer of Nb-Permalloy/Ta/glass-disk. Mn-Ir(001) film was obtained on MgO/glass-disk. On the other hand, Nb-Permalloy was found to exhibit [110] orientation at sputtering temperatures between 200/spl deg/C and 400/spl deg/C on the MgO layer, thus Mn-Ir(110) was first realized on the underlayer of Nb-Permalloy/MgO/glass-disk. The exchange-bias fields, H/sub ex/, and possibility of increasing the H/sub ex/ were investigated.