Correlation between the thermal expansion coefficient and heat capacity of an inert-gas single crystal: Krypton

Correlation dependence of volumetric thermal expansion coefficient o$(T)$ on heat capacity $C(T)$ for single-crystal krypton is studied. It is shown that the dependence o$(C)$ is observed not only at low temperatures, where it is linear and is known as the Grüneisen law, but also in a much wider temperature range up to the melting point of krypton. When the specific heat reaches a classical limit of 3R (according to the Dulong–Petit law), the o$(C)$ dependence considerably deviates from the low-temperature linear behavior. The concept of the differential Grüneisen parameter of krypton, $\gamma'\sim(\partial o/\partial C)$, is introduced, and its temperature dependence is estimated.