Magnetic properties of amorphous GdAl and GdCu

Sputtered amoprhous films of Gd0.41Cu0.59 and those with higher concentration of Gd are found to be ferromagnetic with Curie temperatures 75 K and higher. In contrast Gd0.37Al0.63 is found to take a spin glass state with a transition temperature of 15.8 K as defined by a sharp asymmetric cusp in the static susceptibility when measured in low magnetic fields. Below 15.8 K relaxation and thermal hysteresis effects of the susceptibility are found, characteristics of a spin glass. © 1977.