The Specific Heat of Graphite from 13deg; to 300deg;K

摘要

The specific heat of highhyphen;purity Acheson graphite prepared by the National Carbon Company has been measured from 13deg; to 300deg;K. In the region 13deg; to 54deg;K theCpdata follows aT2dependence quite accurately in agreement with previous experimental work and recent theoretical investigations of specific heat in strongly anisotropic solids.On the basis of some recent studies for other highly anisotropic solids, it is suggested that the specific heat of graphite will eventually follow aT3dependence at still lower temperatures.The derived thermodynamic functions, entropy, enthalpy, and free energy, have been determined by graphical integration and tabulated at integral values of temperature up to 300deg;K. The entropy of graphite at 298.16deg;K is 1.372plusmn;0.005 cal/ghyphen;atom deg, of which 0.004 is extrapolated from 13deg; to 0deg;K assuming the third law and theT2dependence.