Magnetic recording carrier - with ferromagnetic cobalt-chromium-platinum alloy thin film

摘要

Novel magnetic recording carrier comprises the following sequence of layers on a non-magnetic substrate (i) a base layer of non-magnetic metal; (ii) a thin film of ferromagnetic alloy of compsn. either (a) max. 15 wt.% Cr, 6-18 wt.% Pt and balance Co or (b) max. 15 wt.% Cr, max. 12 wt.% Pt, 0.15-5.4 wt.% metal element selected from Ta, Hf, W, Zr and Nb, and balance Co; and (iii) a protective layer. Prodn. of a magnetic recording carrier involves. (i) heating a non-magnetic substrate to 160-270 deg.C; (ii) sputtering a non-magnetic metal target to form a base layer on the substrate; (iii) sputtering a ferromagnetic alloy target to form a thin film contg. Co, Cr and Pt on the base layer; and (iv) forming a protective layer on the thin film. USE/ADVANTAGE - The carrier may be a magnetic storage disk, diskette or tape, e.g. for use in tape recorders or external disk memories for data processing units such as computers. It has a very fine grained magnetic layer with an easy magnetisation axis easily oriented in the plane of the carrier so that the carrier has a high coercive force and high rectangularity and is suited to high recording densities.