Charge transfer and the magnetic properties of amorphous Gd_0.33Co_0.67

Magnetization measurements on amorphous Gd0.33Co0.67 films indicate that Tc is>30 per cent higher in the films than in the ordered compound, GdCo2, of the same composition. This reverses the trend observed in isostructural Tb0.33Fe0.67 and many other amorphous ferromagnets, where Tc is lower in the amorphous state. A qualitative explanation of the effect of structural disorder on magnetic properties of the Co and Fe compounds is given in terms of the consequences of charge transfer to the transition metal atoms. © 1973.