Pippard relations for cubic gauche nitrogen

Abstract

The Pippard relations (CP vs. aP and aP vs. kT) are examined at various temperatures up to 1200 K at zero pressure (P = 0) for the cubic gauche nitrogen. The specific heat (CP) is related to the thermal expansion (aP) and the aP is also related to the isothermal compressibility (kT) as the Pippard relations for this solid structure. For those relations, experimental data are used from the literature. It is found that the variation of the CP with the aP and aP with the kT is linear. Using the linear relations dP/dT is predicted, which can be compared with the experimental measurements in the P – T phase diagram of cubic gauche nitrogen.