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Low-Temperature Specific Heat of 4He Films in Restricted Geometries

  • R. H. Tait
  • R. O. Pohl
  • J. D. Reppy

Abstract

Confinement of superfluid helium to a system of random small (~ 100Å) pores markedly affects its properties, as was demonstrated by Pobell et al.1; they observed the oscillations of superfluid helium in a U tube filled with tightly packed lampblack or porous Vycor glass and noted a large increase in the normal fluid density over that of the bulk. At low temperatures they saw a linear dependence of ρ n on T in contrast to the bulk T 4 dependence derived from other experiments. Padmore2 proposed a model for long-wavelength phonons in a “zero-dimensional geometry” that gave a linear temperature dependence and a constant heat capacity at low temperatures given by
$$C = (V/{d^3}){k_B}$$
where V is the total volume of the He II in the porous system, d is the average pore diameter, and k B is Boltzmann’s constant. Heat capacity measurements on helium in disordered, restricted geometries have been made by other workers, but they have only been made at temperatures greater than 0.5°K, which is too high to test Padmore’s prediction. These measurements have also been done on partially filled pores and have pointed out interesting properties of helium films under these conditions.

Keywords

Heat Capacity Heat Capacity Measurement Superfluid Helium Heat Capacity Data Linear Temperature Dependence 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

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Copyright information

© Springer Science+Business Media New York 1974

Authors and Affiliations

  • R. H. Tait
    • 1
  • R. O. Pohl
    • 1
  • J. D. Reppy
    • 1
  1. 1.Laboratory of Atomic and Solid State PhysicsCornell UniversityIthacaUSA

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