Abstract
Measurements of electrical resistivity, AC susceptibility and specific heat on Czochralski-grown single-crystalline UPt3 reveal a transition into a superconducting state below 0.48K. From the experimental value of the upper critical field, dBc2/dT=-4.4 T K-1, and effective mass of 180m0 is deduced. A numerical analysis of the normal-state specific heat data below 20K results in a large T3 ln(T/T*) contribution, indicating pronounced spin-fluctuation effects.