Thermal expansion and elastic constants of single-crystalline UPt3

Thermal expansion measurements have been performed on single-crystalline UPt 3 between 1.4 and 100K. Spin-fluctuation terms dominate the volume expansion at low temperatures. The linear terms in the thermal expansion and the specific heat are compared and a giant value is obtained for the appropriate Gruneisen parameter. The elastic constants of UPt 3 at room temperature have been determined from sound velocity measurements. A value of 0.48 Mbar -1 results for the nearly isotropic compressibility.