| 摘要 |
PURPOSE:To obtain a magnetic recording medium having the high coercive force in the perpendicular direction on a substrate by specifying d/t and (d) to specific values when the average grain size of the columnar crystal forming a magnetic layer is designated as dAngstrom and the film thickness of the magnetic layer as tAngstrom . CONSTITUTION:This magnetic recording medium has the magnetic layer of the columnar crystal structure oriented approximately perpendicularly to the film plane on the substrate. The magnetic layer is so formed as to have 0.19-0.58, more preferably 0.22-0.56 d/t when the average grain size of the columnar crystal forming the magnetic layer is designated as dAngstrom and the film thickness of the magnetic layer is designated as tAngstrom . The average grain size (d) of the columnar crystal of the magnetic layer is made 700-2,100Angstrom , more preferably 800-2,000Angstrom . The magnetic layer is formed on such substrate directly or via an underlying film of a thin metallic film having high magnetic permeability such as 'Permalloy(R)'. An arc discharge ion plating method is preferable as a method for forming said film. The magnetic layer which is a vertically magnetized film is thus formed at a relatively low substrate temp. and high film forming speed and the magnetic layer is provided with the high coercive force in the direction perpendicular to the film plane.
|
