Magnetic Behavior of Gadolinium Near the Curie Point

Magnetization measurements on a single crystal of gadolinium have established that the Curie temperature Tc is 292.5±0.5°K, that the initial susceptibility is given by 1/χ0=A(T−Tc)43 from Tc to 20° above Tc, and that the magnetization is given by σ=CH¼ at Tc. These results are obtained only if measurements are made along the 〈0001〉 easy direction; measurements in other crystallographic directions give significantly different results because the magnetocrystalline anisotropy of Gd is not zero at and above Tc.