| 摘要 |
PURPOSE:To provide a recording medium suitable through the vertical magnetic recording system by forming an Ni-Co-P alloy magnetic film on a non-magnetic substrate. CONSTITUTION:As a base, a rolled copper plate coated with a nickel-phosphor non-magnetic film through the electroless plating is soaked in a plating bath containing nickel chloride with concentration of about 60-80g/l, cobalt chloride with 160-180g/l, ammonium chloride with 50-100g/l and sodium hypophosphate with 4-8g/l and electroplated to form an Ni-Co-P alloy magnetic film. The magnetic film is composed of 61.8wt% Ni, 33.5wt% Co and 4.7wt% P, and according to an X-ray diffraction pattern, a surface 002 only appears as a peak and the axis C of alpha-Co of the hexagonal closest construction is arranged in the direction perpendicular to the film surface, whereas the degree of dispersion represents superior orientation. In other words, the Ni-Co-P alloy magnetic film composed of 55-78wt% Ni, 15-41wt% Co and 3-8wt% P is a vertically magnetized film whose magnetization facilitating axis of the alpha-Co is perpendicular to the film surface and relatively short of dispersion and whose anisotropic constant is large, whereas the coercive force in the vertical direction shows a value as large as about 800-25,000e. |
