Boundary Resistance between PrNi₅ and Liquid ³He

Abstract

We have measured the steady state thermal conduction between. 3He and PrNi5. The PrNi5 sample consisted of 40 µm particles, which were sufficiently large so that the 3He quasiparticle mean free path was not size limited. The sample was heated with eddy currents and the internal temperature was monitored using the susceptibility of the PrNi5. Our results show that the boundary conductance follows T2 between 2 - 15 mK. We also observed a ∼ 3.5 times increase in the conductance as the applied field was increased from 0 to 400 gauss, but no dependence on pressure or the presence of superfluid. While the field dependence cannot be explained, the temperature dependence is that expected for a magnetic spin glass.