RECORDING CHARACTERISTICS OF CO-GAMMA-FE2O3 PERPENDICULAR MAGNETIC RECORDING MEDIA

The recording characteristics of Co-gamma Fe2O3 perpendicular magnetic recording hard disk media were investigated. Sliding contact recordin g was performed to evaluate the intrinsic high-density recording perfo rmance of the media with using a metal-in-gap-type ring head. The half -voltage density D-50 of 176 kFRPI and low-density reproduced voltage E(p) of 143 nV(p-p)/[turn mu m (m/s)] were obtained for the optimal me dium whose Co-gamma Fe2O3 layer thickness was 0.13 mu m and perpendicu lar coercivity was 1800 Oe. The pass wear durability test was performe d at 2 m/s, or at a disk rotation of 830 rpm. The reproduced voltage d id not decrease with time, and scratches and damage were not observed on the tested track even after 18 000 000 passes. The Co-gamma Fe2O3 m edium is one of the candidates for ultrahigh-density recording media b ecause of its specific advantages; superior high density recording per formance and hardness tolerable for sliding contact use. (C) 1996 Amer ican Institute of Physics.