Cu-63 NMR in the unconventional Kondo alloy UCu3.5Pd1.5

Cu-63 quadrupole-split nuclear magnetic resonance has been observed in the unconventional Kondo alloy UCu3.5Pd1.5. The magnetic and quadrupolar line widths were measured as functions of temperature. Below similar to 30 K the magnetic line width is enhanced similar to 25% over the values expected by scaling the high-temperature magnetic susceptibility. This behavior might indicate the possibility of U-spin freezing, as observed in some dilute Kondo alloys. The absence of any anomaly at similar to 30 K in either the specific heat or the susceptibility suggests, however, that spin freezing does not account for the observations, and that the enhancement is related to intrinsic behavior of the paramagnetic alloy.