Initial Susceptibility of Iron and Iron Alloys Just Above Their Curie Temperatures

The volume susceptibility of Fe and dilute alloys of Fe with various solutes have been measured from within 0.05°K of the Curie temperature Tc to 15°K above Tc. The results have been analyzed using the equation χv−1 = [(T−Tc)/T1]γ. The results yield a value of γ = 1.333±0.015 for Fe and its dilute alloys. For Fe T1 = 1.27°±0.01°K, T1 appears to vary rapidly with solute concentration for some solutes. The measurements do not show any temperature dependence of γ within 15°K of Tc.