Order and non-Fermi-liquid behavior in UCu4Pd - art. no. 205116

We have studied the role of disorder in the non-Fermi-liquid system UCu4Pd using annealing as a control parameter. Measurement of the lattice paramete r indicates that this procedure increases the crystallographic order by rea rranging the Pd atoms from the 16e to the 4c sites. We find that the low-te mperature propel-ties depend strongly on annealing. Whereas the non-Fermi-l iquid behavior in the specific heat can be observed over a larger temperatu re range after annealing, the clear non-Fermi-liquid behavior of the resist ivity of the unannealed sample below 10 K disappears. We come to the conclu sion that this argues against the Kondo disorder model as an explanation fo r the non-Fermi-liquid properties of both as-prepared and annealed UCu4Pd.