Specific heat ofUPt3at the metamagnetic phase transition

Abstract

We present results of specific-heat measurements on a high-quality single crystal of the heavy-fermion compound ${\mathrm{UPt}}_3$ in the temperature range from 0.5 to 3 K in steady magnetic fields up to 26 T with the field direction along the a axis of the hexagonal crystal structure. At low temperature, the specific heat shows a maximum at the metamagnetic phase transition with a critical field of 20.3 T. We compare our results to other high-field properties and discuss a possible relation to the c/a lattice ratio and to a similar behavior found in ${\mathrm{CeRu}}_2$ ${\mathrm{Si}}_2$.