The Paramagnetic Susceptibility of Copper-Nickel and Zinc-Nickel Alloys

Alloys of nickel were prepared with 0 to 60 percent copper or 0 to 30 percent zinc. Their susceptibilities above their Curie temperatures were measured as a function of the temperatures using a Weiss-Fo\"ex magnetic balance at a field of 11,000. Plots of 1χ against T showed that the Curie-Weiss law holds only in restricted ranges of temperature, the curve becoming concave towards the T axis at high temperatures, especially for the alloys of low nickel content. The susceptibility at a given temperature decreases less rapidly than linearly with percent copper or zinc added. These results are discussed from the points of view of the Heisenberg and the Bloch models.