Theory of the Curie temperatures of the rare earth metals

Abstract

The curie temperatures of the rare earth metals have been calculated ab initio using the local pin density approximation. The exchange splitting of the 5d-states depends upon local 4f-5d exchange integrals, κ 415d, which are calculated ab initio in the local spin density approximation. The Curie temperatures may then be obtained without use of adjustable parameters but are calculated to be too high by a factors of two to three if normal itinerant electron mean field theory is used. We have found that it is necessary allow for disordered local 5d moments above T c and to calculate the local susceptibility. When the local fluctuation contribution to the Landau Parameter, A, is included the Curie temperatures are actually reduced to below those measured.