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 T³ arising from lowfrequency lattice waves and a term proportional to T due to electrons: C=0.0325T³+0.031T millijoules/mole degree. Between 2.25^∘{}K and 4.5^∘{}K, C=0.115T²+0.031T-0.237 millijoules/mole degree; between 10 20^∘{}K, C=0.208T²-6.8 millijoules/mole degree.