Microscopic Fermi liquid theory of the temperature dependence of the susceptibility of normal paramagnetic metals

Abstract

A microscopic theory of Fermi liquids is used to study the temperature dependence of the susceptibility chi (T) of normal paramagnetic metals. A T² ln T variation is proved to exist in the case of spin-independent forces. This variation agrees with Misawa's calculations based on phenomenological Landau theory. Previous theories by Stoner (1938), Beal-Monod et al. (1968) and Kawabata (1974) are critically discussed. The T² ln T term provides an explanation for the maximum in chi (T) observed in many metals as well as for the overall temperature dependence at low temperatures. Comparison with experiments on Pd, U₂C₃, YCo₂, LuCo₂, He³ and Ni₃Ga is given. The coefficient of the T² ln T term is calculated within the 'paramagnon model'. The effects of impurities and imperfect order are studied and are found to suppress the maximum in chi (T). This provides an explanation to the observed behaviour in different palladium alloys as well as to the lack of a maximum in Ni₃Ga.