Newly developed SmCo₅ thin film with perpendicular magnetic anisotropy

A sputter-deposited SmCo₅ thin film with perpendicular magnetic anisotropy has been developed. The Sm-Co film, composed of [Co (0.41 nm)/Sm (0.31 nm)]₃₅, was prepared by sputtering on a Cu (100 nm)/glass substrate at various substrate temperatures. The coercivity was found to increase rapidly at 325-345°C and to be much greater in the direction perpendicular to the film surface than in the film plane. By using in-plane x-ray diffractometry, reflection peaks of the Sm-Co film deposited at 325-345°C were confirmed to originate from the SmCo₅ phase, and the film showed a preferred orientation of the c-axis in the direction perpendicular to the film surface. The Co/Sm laminate structure deposited on the Cu seedlayer at an appropriate substrate temperature was found to be the key to promoting crystallization of the SmCo₅ with its c-axis oriented perpendicular to the film surface.