Magnetization Studies on Tb-Fe and Tb-Fe-Co Thin Films

Magnetization studies were carried out on Tb-Fe and Tb-Fe-Co thin films, prepared using magnetron co-sputtering technique. The films Tb25Fe75 and Tb31Fe69 were found to have perpendicular magnetic anisotropy (PMA) both at 25 and 300 K. In Tb-Fe-Co films, all the films were observed to exhibit planar anisotropy at 25 K, due to the increase of strain-induced anisotropy as a result of large magnetostriction at low temperatures leading to the development of in-plane anisotropy. PMA was observed in the films Tb35Fe37Co28, Tb56Fe25Co19, and Tb63Fe20Co17 at 300 K. The Curie temperatures (T-C) of both TbxFe100-x and Tb-Fe-Co films were found to be above room temperature (RT). Observing the Curie temperatures well above the RT, with the existence of PMA at RTs, is an interesting object in these films to find in magnetic data storage applications.