IMPROVEMENT OF THE MAGNETIC-PROPERTIES OF CO-CR LAYERS BY PLASMA PRETREATMENT OF THE POLYMERIC SUBSTRATE

The influence of various pretreatment methods like plasma etching and ion beam etching of PET (polyethylene terephthalate) and PI (polyimide ) foil substrates on the static magnetic properties and the recording behaviour of CO74Cr26 (300 nm) films deposited at room temperature has been investigated. By the pretreatment the saturation magnetization M (s) and the vertical coercivity H-c,H-z of the Co-Cr layers can be tai lored to the values required for improved recording characteristics (M (s) greater than or equal to 400 kA/m, H-c,H-z greater than or equal t o 40 kA/m). Indications of a Cr segregation in the Co-Cr layer induced by the pretreatment of the substrate have been found.