Effect of high magnetic fields on the heat capacity of strongly Pauli-paramagnetic Pd-Ni alloys

Abstract

The low-temperature [(1.3-20.0)-K] heat capacity of strongly Pauli-paramagnetic Pd-Ni alloys containing 0.47 and 0.97 at.% Ni was measured in magnetic fields up to 10 T. The electronic specific-heat constant becomes smaller with increasing fields (12% or 13% at 9.98 T). This is probably due to the depression of the spin-fluctuation enhancement of heat capacity by the high magnetic fields and is in accord with the recent theoretical predictions. The coefficient $\beta$ of the $T^3$ term in the heat capacity becomes larger with increasing fields and at $H\ge 5.39$ T it reaches almost the same value as that for alloys containing more than ∼5 at.% Ni. Two possible mechanisms have been proposed to account for the increase in $\beta$: (1) The increase is due to the magnetic quenching of localized spin fluctuations in the vicinity of the nickel atoms, or (2) the increase is due to a magnetic contribution to the heat capacity which results from an induced magnetic moment on the nickel atoms by the applied magnetic field. Additional experiments are needed to determine which mechanism is the correct one.