HYBRIDIZATION EFFECTS IN UCU5-XAUX COMPOUNDS

We review the results of bulk and neutron diffraction measurements on the UCu5-xAux system crystallizing in the cubic AuBe5-type structure. The observed properties may be understood in the light of competition between Kondo effect and RKKY exchange interactions. Effects of 5f-lig and hybridization between the U-atoms occupying the 4a-sites and the A u- or/and Cu-atoms placed at the 4c- and 16e-positions, respectively, are supposed to be different. We show that the prefential occupation o f 4c-sites by Au has a marked effect on the magnetic properties of the investigated system.