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 tailored 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 to 40 kA/m). Indications of a Cr segregation in the Co-Cr layer induced by the pretreatment of the substrate have been found.