Ferromagnetic thin films prepared by ion plating

Thin films of Co, Ni and their alloys were prepared by ion plating. Metals were evaporated in an Ar gas atmosphere of about 0.01 torr, while applying a dc electric field of 2 kV/ 15 cm between the substrate and the evaporation source. Since metal atoms, which were given large kinetic energy by the gas plasma, impinged on the surface of the substrate, a strong adhesion between the ferromagnetic film and the substrate could be obtained. By changing the Ar gas pressure, the coercive force of the film could be controlled up to a maximum of 500 Oe and also by choosing the constituents of the mother alloys. Magnetoresistance of the film was also measured. The change of the resistance was 2.1%, when the cobalt concentration was 50 %.