MAGNETIC TRANSITION IN THE HEAVY-FERMION COMPOUND URU2-XREXSI2

On partially substituting Ru atoms by Re in the well-known antiferroma gnetic superconductor URu2Si2 an itinerant ferromagnetic state progres sively develops. Simultaneously the partial gap at the Fermi surface, associated with the formation of a spin density wave ground state in t he undoped material, is closed. We present point-contact measurements of the system URu2-xRexSi2 with x in the range 0-0.8. A maximum around zero bias in the differential resistance of URu2Si2 is assumed to rep resent the spin density wave gap on the Fermi surface. The influence o f the Re substitution on the maximum as well as the temperature and ma gnetic held dependence of the zero bias structure are presented.