Systematic measurements of the heat capacity in the B phase of superfluid 3He disordered by impurities were described. For the experiment, low temperature calorimeter was cooled with a PrNii5 adiabatic nuclear demagnetization refrigerator to temperatures below 0.75 mK above which heat capacity was measured using an adiabatic calorimetric method. The calorimeter volume was found to be 1.91± 0.02 cm3 with the aerogel sample in place, leaving 44% of the space available for bulk 3 He. It was concluded that the limiting temperature dependence of the specific heat is linear at low temperature in the disordered superfluid state, consistent with predictions of gapless excitations.
ASJC Scopus subject areas
- Physics and Astronomy(all)