Magnetization data are presented on D.C sputtered amorphous RCox films where R=Gd, Dy, Ho, Er, and x=2.1−4.9. The Curie temperatures of the four RCo3.5 alloys are found to be very close to each other confirming the absence of charge transfer in the amorphous state. At low temperatures a 15–20% reduction in the R contribution to the magnetization is observed, probably due to local anisotropy fluctuations. Stripe domains are obtained at room temperature in Gd, Dy, Ho compounds; Gd and Ho films exhibit similar anisotropy energies. The existence of perpendicualr anisotropy seems to be independent of the R constituent, but is influenced by the bias conditions during deposition.