Atomic Heat of Graphite between 1 and 20°K

The atomic heat of pure artificial polycrystalline graphite has been measured between 1 and 4°K and 10 and 20°K. Precautions were taken to ensure that no error was introduced by gas adsorbed on the graphite. Below 2°K the atomic heat can be represented as the sum of a term proportional to $T^3$ arising from lowfrequency lattice waves and a term proportional to $T$ due to electrons: $C=0.0325\mathrm{}{T}^3+0.031T$ millijoules/mole degree. Between 2.25°K and 4.5°K, $C=0.115\mathrm{}{T}^2+0.031T-0.237\mathrm{}$ millijoules/mole degree; between 10 20°K, $C=0.208\mathrm{}{T}^2-6.8\mathrm{}$ millijoules/mole degree.