Metamagnetic transition inUPt3studied by high-field magnetization and de Haas–van Alphen experiments

Abstract

A heavy fermion superconductor ${\mathrm{UPt}}_{3}$ exhibits the metamagnetic transition at about 20 T. High-field magnetization experiments reveal that this transition persists up to about 30 K, which is close to the characteristic temperature ${T}_{\ensuremath{\chi}\mathrm{max}} (\ensuremath{\simeq}20$ K) where the magnetic susceptibility has a maximum in the temperature dependence. Below ${T}_{\ensuremath{\chi}\mathrm{max}},$ the magnitude of magnetic fluctuations increases and forms the heavy fermion state at low temperatures. This is reflected in the growth of the cyclotron effective mass. The mass in the main band 37-electron Fermi surface, which was determined by the de Haas--van Alphen experiments, is strongly enhanced with increasing the field, from ${63m}_{0}$ at 12.5 T to ${86m}_{0}$ at 18 T. This is consistent with the field dependence of the electronic specific heat coefficient.