A simple method for tuning perpendicular magnetic properties of ultra-thin TbFeCo films

Ultra-thin amorphous TbFeCo films with perpendicular magnetic anisotropy (PMA) are sputtered. The PMA of the alloy films is found to be strongly related to the thickness. A critical thickness is observed to exist, where a transition from a FeCo-dominant to a Tb-dominant configuration occurs. Large variation of magnetic properties is demonstrated for the film in the thickness range across this critical thickness. Our results show the critical thickness may be used as an alternative way to tune the perpendicular magnetic properties of the ultra-thin TbFeCo films.