EVIDENCE FOR THE FORMATION OF THE SPIN-GLASS STATE IN U2PDSI3

Results of de magnetization, magnetic relaxation, specific heat, and e lectrical resistivity measurements on a well-annealed polycrystalline U2PdSi3 sample are reported. The temperature dependence of the de magn etization exhibits a cusp at a characteristic temperature T-f that str ongly depends on the applied magnetic field. Below T-f, the magnetic r elaxation measurements reveal a decay of the isothermal remanent magne tization vs time that is drastically slower than above T-f. No anomali es around T-f are observed in the specific heat and electrical resisti vity data, which rules out the existence of usual long-range spatial m agnetic order. These results can be considered as clear evidence for t he formation of a spin-glass state in U2PdSi3 with a freezing temperat ure T-f = 13.5 K. The necessary randomness in the U-U magnetic exchang e interactions arises from a statistical distribution of Pd and Si ato ms on a crystallographic site of the U2PdSi3 crystal lattice.