Thermal relaxation calorimetry below 1 K

Abstract

The thermal relaxation method is used to measure heat capacities of small samples from 0.060 to 1.2 K. The calorimeter incorporates a low heat capacity holder, and is designed to be used in conjunction with a ³He–⁴He dilution refrigerator. The accuracy was checked by measuring a 2 g copper sample. A least squares fit of the copper data yields a γ value of 0.688 mJ (K²g at.)⁻¹ which agrees to 1.0% with published values of γ for copper. The data exhibit a standard deviation of 5.6% around the fit.