HYBRIDIZATION EFFECTS IN SOME UX_5 COMPOUNDS

摘要

The presence of the magnetic moments on the uranium atoms in some of the UX_(5-x)Y_x compounds (X and Y are 3d, Ad or 5d transition element) is discussed using the hybridization strength of the s, p, d and f atomic orbitals. By using a semi quantitative band structure approach due to Straub and Harrison, the hybridization effects in these binary and ternary series of isoslructural compounds were evaluated. Comparing the bandwidth with a theoretical critical energy (for f~2 and f~3) in order to predict if the ground state is magnetically ordered it seems that/3 is not the exact electronic configuration for uranium in this class. This fact is correlated with the suggestion that the U valence in the UCu_5 group is a mixture of values where the tetravalent component (f~2 configuration) is a significant one.