Magnetic Properties of SmCo Sputter-Deposited Polycrystalline Films

SmCo polycrystalline films were sputter-formed on glass substrates at temperatures between 200 and 300°C, and relations between precipitated phases and film magnetic properties were studied. Phases with Sm-Co stoichiometric ratios of 2-17, 1-5, 1-3, and 1-2 were tentatively identified; these phases exhibit widely varying coercivities, in the ranges of several hundred Oe, several kOe, around 10 kOe, and under 100 Oe, respectively. Except SmCo₂, all other phases, which were of hexagonal structure, resulted in a large negative K_u value for the film.