On the specific heat of the sodium chloride crystal

Abstract

Based upon previous calculations of about 280 proper frequencies of the sodium chloride lattice, these frequencies have been used to determine the specific heat of NaCl according to Born’s theory. It is shown that this number of frequencies is sufficiently large to make the determination of the frequency distribution and, therefore, of the specific heat possible. Agreement with experiment is obtained. It is shown in agreement with Blackman’s investigations that the deviations from Debye’s theory as found experimentally are due to Debye’s assumption of a v 2 law for the frequency distribution instead of the distribution following from the atomic theory.