Effect of finite f level linewidth on the theory of the α-γ transition in Ce

Abstract

The Ramirez-Falicov theory of the alpha - gamma transition in Ce is extended to include the effect of hybridization of the localized 4f states with the band. The physical properties of the alpha and gamma phases are calculated using thermodynamic Green functions which are determined by a decoupling procedure that accounts for the highly correlated character of the f levels. The decoupling procedure is exact to second order in the hybridization parameter. Satisfactory values are found for the noninteger valency, electronic specific heat and magnetic susceptibility of the alpha phase. A Curie law for the gamma phase is also obtained.