New evidence for spin glass states in U2TSi3 (T = Pd, Pt and An):: AC susceptibility and electrical resistivity

The uranium intermetallic compounds U2TSi3 (T = Pd, Pt and Au), which crystallize in a disordered derivative of the hexagonal AIB(2)-type structure, have been studied by means of ac susceptibility and electrical resistivity measurements. The experimental results and the dynamical analyses give new and important evidence for the formation of spin glass states in these systems. The origin of spin glass behavior for U2TSi3 is different from that for diluted metallic material or rare-earth intermetallic compounds. The competition between ferromagnetic and antiferromagnetic exchange couplings mainly mediated by the 5f-ligand hybridization in U2TSi3 is considered to originate from the random distribution of T and Si atoms in the crystal lattice.