Low-Temperature Specific Heats of Solid Neon and Solid Xenon

Abstract

The specific heats of solid neon and xenon have been measured in the temperature range 1.5 to 24°K, using a calorimeter with a mechanical heat switch. Carbon resistance thermometers were calibrated against a gas thermometer and the helium vapor-pressure scale. The results were analyzed to obtain the temperature dependence of the Debye temperature, в с (Г). In the range 0.020<Г/в 0 с <0.505, the data were fitted with an expression of the form В с (Т)=во с +АТ 2 ,where G 0 C is the Debye temperature at 0°K. This procedure gave 0 o c =74.6dbl.O°K for neon and е 0 с = 64.0±0.8°К for xenon. The results for в с (Т) are compared with the calculations of Bernardes, Horton, and Leech, and Barron and Klein, based on Mie-Lennard-Jones potentials for the interaction energy between two atoms. Tables of the following smoothed thermodynamic properties between 1.0 and 24°K are given in Table I: specific heat at constant pressure, specific heat at constant volume, entropy, and enthalpy.

The sublimation of argon, krypton, and xenon

“…Combining the average of these two figures for D ' s H m ðT ¼ T t Þ with the above mentioned value of the enthalpy of vaporization at T t , the enthalpy of sublimation at the triple point is obtained from equation (5) For the heat capacity of the three monatomic elements in the gaseous state at the low pressures involved along the sublimation equilibrium, the classical value C g p;m ¼ ð5=2ÞR has been used in our calculations. Concerning the heat capacity of each of the three elements in the solid state, the experimental values [12,[14][15][16][17][18] have been expressed by simple polynomial functions of temperature:…”

Dislocation Structure and Mobility in Hcp Rare-Gas Solids: Quantum versus Classical

“…It is appreciated that, in spite of the absence of shear stresses, the dislocation moves at temperatures as low as 25 K, which are well below the corresponding Debye temperature (Θ D ∼ 65 K [16]). (Cautiously, we have monitored the size of the fluctuating stresses in our MD simulations, which are null in average, and checked that in fact they are not responsible for the observed dislocation glide (e.g., σ fluctuations τ P in the (N, P, T) runs).…”

“…We find that the Peierls stress for the glide of edge dislocations in the hcp basal plane amounts to ∼1 MPa, which is very similar in magnitude to the values reported for classical metals with the hcp structure (e.g., Zr and Cd) [12,13]. However, in contrast to other classical solids but in analogy to solid helium, edge dislocations in hcp rare gases turn out to be extremely mobile: they can diffuse with an approximate velocity of 50 m/s in the absence of any applied stress at temperatures as low as 25 K (that is, well below the corresponding Debye temperature Θ D ∼ 65 K [16]). We rationalize the origins of this effect in terms of the exceptionally weak interatomic interactions in rare gases.…”

Channeling in solid Xe, Ar and Ne direct dark matter detectors

“…The Debye temperatures of Xe, Ar and Ne are Θ Xe = 55 K, Θ Ar = 85 K and Θ Ne = 63 K [29,30], and the crystals in the Solid Xe R&D Project experiment will be operating at a temperature of 77.2 K or higher [25].…”