Magnetism in Ni-Cu alloys

Very low field (<1 Oe) magnetization measurements on Ni-Cu alloys are reported. The magnetic properties depend sensitively on the metallurgical state. For concentrations less than 45 at.% Ni, a spin glass-like or micto- magnetic freezing is observed, signaled by a cusp in the a.c. susceptibility. Above 45 at.% Ni the alloys are ferromagnetic.