Effects of Activation and Acceleration on Magnetic Properties of Chemically Deposited Co-P Thin Films

The effects of pretreatment (i.e., activation and acceleration) and substrate species on the magnetic properties of Co-P electrolessly plated thin films for high density storage medium were investigated with various PdC1₂/SnC1₂catalysts and accelerators. The activity of surfaces to be plated controlled the magnetic properties of Co-P thin films, and the coercivity became lower with increase in the catalytic activity of surfaces. The magnetic properties of Co-P films were also affected by the substrate species and were controlled by grain size of substrate surfaces, but the larger surface roughness which was produced by emery papers did not affect the magnetic properties. The Co-P thin film on acetylcellulose whose coercivity was the highest in the experiments was investigated with transmission electron diffraction analysis. The pretreatment for electroless plating was observed to influence not only the distribution of crystallite grain sizes but also the orientation of the c-axis of the hexagonal a-cobalt lattice plated onto acetylcellulose.