Date of this Version
Physical Review B, Volume 46, Number 14, October 1992
In this paper we present a thermodynamic analysis of the UPt3 superconducting phase diagram in the H-T plane. The analysis relates the specific-heat jumps to the slopes of the four phase-transition lines. The existing data are found to be in good mutual agreement, and consistent with the assumption that the inner phase-transition line at low field, Tc*, is second order for both Ĥll ĉ and Ĥll ĉ. For Ĥllĉ, the inner phase-transition line at higher field, HFL, is first order albeit with a small latent heat. For Ĥll ĉ, it can be second order.