Production of magnetic recording medium

摘要

A magnetic recording material includes a substrate (20) of polyethyleneterephthalate foil that is transferred from a supply reel (22) to a wind up reel (24). Guide rollers (26a,26b) maintain a controlled tension in the substrate. The substrate is passed over a cooling plate (30) that uses a cooling medium of water with other liq. or gas additions. A target element (32) of Co-Cr alloy is used to form the alloy layer on the substrate. Cobalt or chromium atoms are released by generating ions of an inert gas, such as Argon, using an atomising process. The particles form on the substrate surface and the coercive force is varied by adjusting the substrate distance (d) upto 10 mm.