ANALYTIC APPROXIMATION OF THE DEBYE FUNCTION

Abstract

An expression in a closed form is proposed for the approximation of the Debye function used in thermodynamic models of solids. This expression defines an analytic function that has the same limiting behavior as the Debye function at low and high temperatures. The approximation gives the maximum relative deviation from the value of the Debye function less than 0.001. The proposed expression can be useful in the equations of state of solids in a wide temperature range.