The heat capacity of diamond between 12·8° and 277°k

Abstract

The heat capacity of 160 g of diamonds has been measured in the temperature range 12·8° to 277°k with estimated accuracies of ±20% at 13°k, ±6% at 20°k, ±0·8% at 100°k and ±0·2% for T200°k. Fitting of the results in the region T<θ_d/20 to the low temperature expansion for the heat capacity gives θ₀ = 2219 ± 20°k; this agrees excellently with θ (elastic) = 2240 ± 5°k, derived from elastic constants determined by McSkimin and Bond. Down to 75°k the results are in reasonable agreement with earlier measurements of DeSorbo, but at lower temperatures an anomaly reported by DeSorbo has not been confirmed.