Abstract
CoNi ferrite thin films were prepared for perpendicular magnetic recording media by spin-spray ferrite-plating method. In this paper, solution conditions for CoNi ferrite plating were optimized to increase coercivity Hc⊥ and remanence ratio (Mr/Ms)⊥ in perpendicular direction to the film plane. By adjusting the deposition rate, the concentration of NaNO2 to optimize the ratio of Fe2+ to Fe3+ in the films and the concentration of CH3COONH4 to optimize pH in oxidizing solution, CoNi ferrite films with Hc⊥ of 3200 Oe and (Mr/Ms)⊥ of 0.6 were obtained without any heattreatment. Disk media prepared under the optimized solution conditions exhibited reproduced waveforms of dipluse shape and better frequency responses than that with lower Hc⊥ and (Mr/Ms)⊥.
