高密度記録用耐食性Co-Pt合金磁性薄膜

抄録

Co_1-xPt_x(x=0−0.60) thin films prepared by r.f. diode sputtering have been described as a new material for high density longituginal recording medium, which does not need a thick overcoat as a plated Co-Ni-P thin film and which has higher remanent flux density than ferrite thin film, having excellent corrosion resistivity and magnetic properties. The maximum H_c value is obtained at around 20 at. % Pt. Magnetic characteristics, such as H_c, B_s and squareness, of Co_0.80Pt_0.20 film are 1,100 Oe, 12,000 G and 0.90 respectively at 1,000 Å thickness. These values are not changed over 1∼15 Watt/cm² power density corresponding to 58∼850 Å/min. The films, more than 28at. % Pt, have no Bs change after immersion in water for over one month. Ni additive effects in Co-Pt films on magnetic properties and corrosion-resistivity are also described.
Further, 51,000 FRPI linear recording density was obtained, as D₅₀, using a Co_0.70Ni_0.10Pt_0.20 thin film disc and a 0.46 μm gap length head at 0.12 μm head-medium spacing.