Dependence of the CeNi 5 thermoelectric power on strong 4f-electron instability

Abstract

Results of investigation of thermoelectric power component S f related to the valence instability of Ce were presented for solid solutions Ce(M x Ni 1− x ) 5 with M=Ga, Cu (0≤ x≤0.4) in the temperature range 4–900 K. It follows from the analysis of the S f ( T) behavior that when Ce changes from a state of ordinary intermediate valence to a saturated valence, the peculiarity near the Fermi level in the form of a density of states peak of Lorentzian shape transforms into a double-humped structure with quasi-gap formation, Δ∼400 K. The possibility of a certain delocalization of f-orbitals during the transition to the saturated valence of Ce has been discussed.