论文信息 - Thermal Expansion at Low Temperatures III. Potassium Chloride

Thermal Expansion at Low Temperatures III. Potassium Chloride

AbstractObservations of the linear thermal expansion of a potassium chloride crystal have been made between 2° and 30°k, 55° and 90°k, and 273° and 293°k. At the lowest temperatures (3° < T < 9°k), the linear coefficient of expansion α≃5·4±0·3 × 10−11 T3 per °c, which corresponds to a Gruneisen γ value of 0·39 ± 0·2. γ increases with temperature, particularly in the range 15° to 70°k (cf. θD≃235°k), being about 0°9 at 30°k, 1·25 (60°k) and 1·5 above 200°k. This increase is of the form suggested theoretically by Barron and by Blackman for ionic cubic solids but is greater than they expected. It is not very different from that predicted by Sheard from the pressure variation of the elastic constants.

G. K. Whits

[1] G. White. Thermal Expansion at Low Temperatures , 1960, Nature.

[2] J. Dryden,et al. The Intensity of Dielectric Absorption in Alkali Halides as a Function of the Concentration of Divalent Cation Impurities , 1960 .

[3] F. Sheard. Calculation of the thermal expansion of solids from the third-order elastic constants , 1958 .

[4] M. Norwood,et al. Elastic Constants of Potassium Iodide and Potassium Chloride , 1958 .

[5] J. A. Morrison,et al. The thermal properties of alkali halide crystals II. Analysis of experimental results , 1957, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[6] J. A. Morrison,et al. The thermal properties of alkali halide crystals. I. The heat capacity of potassium chloride, potassium bromide, potassium iodide and sodium iodide between 2.8 and 270˚K , 1957, Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences.

[7] M. Blackman. On the Thermal Expansion of Solids , 1957 .

[8] T. Barron. LXXXII. On the thermal expansion of solids at low temperatures , 1955 .

[9] D. Lazarus. The Variation of the Adiabatic Elastic Constants of KCl, NaCl, CuZn, Cu, and Al with Pressure to 10,000 Bars , 1949 .