Temperature and volume dependence of the thermal conductivity of solid neon

The thermal conductivity κ of solid natural neon has been measured by the linear-flow method for specimens isobarically frozen from the dense-fluid phase within a high-strength steel cell. By crossing the fusion curve at several different pressures to as high as 7 ×{} 10³ bars, crystalline samples with molar volumes between 11.16 and 13.35 cm³/mole were grown, and for each the isochoric variation of κ vs T was determined at a set of temperatures in the experimentally accessible range between 5 and 40 K. The large magnitude of κ and reproducibility of the results demonstrate that the present method of preparation and manipulation of solid neon consistently yields good-quality specimens. An analysis utilizing the zero-degree limit of the Debye temperature Θ₀ to account for all volume dependence indicates that the array of data, when expressed in terms of the resistive mean free path, may be rendered into a single function of the inverse reduced temperature Θ₀T. The exponential variation of this common curve over more than 2 orders of magnitude is characteristic of three-phonon umklapp scattering and thereby gives support to Peierls's model of heat transport in dielectric crystals. More recent first-principles theoretical calculations are in qualitative agreement with experiment but yield conductivities somewhat below the observed values.