Evidence for Magnetic Coupling in the Thermal Boundary Resistance between LiquidHe3and Platinum

The first measurements are reported showing that the thermal boundary resistance between a metal and liquid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ depends on the applied magnetic field. The resistance, which is not affected by pressure changes or superfluidity of the liquid, is insensitive to fields less than 2 kG, but increases by a factor of 3 when the field is increased to 8 kG. The experimental results are explained by a model which assumes that the thermal transfer between the Pt and ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ is due to a magnetic coupling between the magnetic moments of conduction electrons in the metal and the nuclear spins of the solid ${}_{}{}^3{}_{}{}^{}\mathrm{He}$ layer on the Pt surface.