Patent number: 4743491
Abstract: A perpendicular magnetic recording medium according to this invention comprises an electrically conductive underlayer formed on a non-magnetic substrate, in the case where no high permeability magnetic film is deposited, and a magnetic thin film having a perpendicular magnetic anisotrophy is formed thereon. In the case of a so-called double-layer structure including a high permeablilty magnetic film, on the non-magnetic substrate are formed the high permeablilty magnetic film, an intermediate film, and a magnetic thin film one on another in this order. The nearest neighbor's distance of atoms of the underlayer and the intermediate film is not smaller than 0.25 nm (2.5 .ANG.) and not greater than 0.32 nm (3.2 .ANG.) and they are made of at least one selected from the group consisting of V, Ru, Zn, Os, Rh, Ir, Mo, W, Re, Pd, Pt, Nb, Ta, Sn, Al, Au, Ag, Ti, nitrides and oxides of these elements.
Type:
Grant
Filed:
November 1, 1985
Date of Patent:
May 10, 1988
Assignees:
Hitachi, Ltd., Hitachi Maxell, Ltd.
Inventors:
Seiichi Asada, Hiroyuki Suzuki, Toshio Niihara, Kazuetsu Yoshida, Masaaki Futamoto, Yukio Honda, Norikazu Tsumita, Kazuo Shiiki