Thermal Boundary Resistance between Pt and Liquid 3He at Very Low Temperatures
For many materials immersed in either liquid 3He or liquid 4He the low-temperature thermal boundary resistance is found to vary approximately as 1/T 3. This behavior is often discussed in terms of the acoustic mismatch theory1 in which phonons are assumed responsible for transferring thermal energy between the solid and the liquid helium. At least one system has been found for which the phonon resistance is not the limiting low-temperature resistance. That system is cerium magnesium nitrate (CMN) immersed in liquid 3He, for which the very low-temperature thermal boundary resistance is found experimentally to vary linearly with the temperature2 and to decrease in the presence of a small magnetic field.3 This resistance has been discussed4,5 in terms of thermal energy exchange via a surface magnetic coupling between the cerium spins of the CMN and the 3He nuclear spins. In this paper we present data which suggest that the thermal boundary resistance between Pt and liquid 3He is qualitatively different from the phonon and magnetic boundary resistances mentioned above.
KeywordsMagnesium Helium Cerium Cerium Magnesium
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