Finite temperature magnetism in Gd: evidence against a Stoner behavior

Abstract

The temperature dependence of the rare-earth valence bands has been regarded as a realization of the Stoner behavior. The exchange splitting of the electronic states appears to scale as the magnetic order parameter for T<T_C and to vanish at T = T_C. We report here a spin-resolved photoemission study on the evolution of Gd bulk bands for 0.5≤ T/T_C≤ 1. The spin-polarized spectral line shapes display a complex temperature dependence, which clearly contrasts with the interpretation of previous experimental results. The spin-resolved photoemission data demonstrate the inadequacy of the Stoner model to the description of magnetism in rare earths.