Non-Fermi-liquid and magnetic behaviour of the Y1-xUxPd3 system

The Y1-xUxPd3 system exhibits an unconventional Kondo effect with non-Fermi-liquid characteristics at low temperatures for x < or approx. 0.2. Measurements of the low-temperature electrical resistivity and magnetization of high-purity samples with 0.05≤x≤0.15 have been made as part of an effort to determine whether the non-Fermi-liquid behaviour persists to low U concentrations, i.e., whether it is a single-ion effect. Irreversible behaviour in the magnetization, reminiscent of spin glass freezing, is observed for samples with 0.25≤x≤0.55, while long-range antiferromagnetic ordering has previously been established by neutron diffraction measurements for a sample with x=0.45. Magnetic relaxation, ac magnetic susceptibility, and specific heat measurements were performed to investigate this unusual magnetic ordering. (author)