Effect of palladium nuclei insertion by electroless deposition on magnetic intergranular isolation and read/write characteristics in SmCo₅ perpendicular magnetic recording media

In order to improve the magnetic intergranular isolation between the magnetic grains in the SmCo₅ perpendicular magnetic recording media, the palladium nuclei deposited by an electrochemical process were introduced into a sputter deposition process of the SmCo₅ film. A few nanometer size Pd nuclei were electrochemically deposited on the sputtered Cu underlayer by a displacement deposition (chemical plating). The sizes of Pd nuclei were controlled by adjusting the Pd ion concentration in electrolyte solutions. The magnetic domain size in Sm-Co layer deposited on Pd nuclei / Cu / Ti underlayer became smaller and the magnetization reversal process was changed from the wall motion to the coherent rotation. Moreover, the read/write characteristics were improved at higher linear recording densities.