Substrate bias voltage dependences of the magnetic and magneto-optical properties in amorphous Tb-Co and Dy-Co films.

Abstract

Magnetic and magneto-optical properties of amorphous Tb-Co and Dy-Co films prepared by R. F. sputtering were investigated. Magnetic properties such as 4πM_s, θ_k, T_c, T_comp and X-ray halo pattern hardly change in the region of positive substrate bias voltage (V_b). On the other hand, they change considerably by increasing negative V_b from 0V to -150V because rare-earth atoms of the films are resputtered preferentially. V_b dependences of perpendicular magnetic anisotropy (K_u) of amorphous Tb-Co and Dy-Co films show minimum values around the V_b’s of -60V and -80V, respectively. These phenomena seem to be explainable in terms of a change of microscopic structure which originates from the preferential resputtering effect.