On the residual magnetoresistivities of heavy-fermion alloys

Abstract

Based on the two-conduction-band periodic Anderson model, including the effects of Kondo holes and conduction band impurities, the residual magnetoresistivities (MRS) of heavy-fermion (HF) alloys have been calculated in the single-site coherent-potential approximation. The strong correlation of HF systems is treated by the slave-boson technique. Our results show that only negative residual MRS can be obtained in 'pure' Kondo-hole alloys and only positive residual MRS can be obtained in 'pure' conduction band impurity alloys. In realistic alloy systems, competition exists between the above two kinds of disorder, which may give rise to a transition in the residual MR from positive to negative with increase in the Kondo-hole concentration.