Relationship between elastic constants and thermal expansivity for ionic solids

In the present communication a relationship between elastic constants and thermal expansivity is disclosed in high temperature region at atmospheric pressure. The relationship is shown for ionic solids viz. NaCl, KCl, CaO and MgO. The analysis is based on the experimental data tabulated by Anderson [Equation of State for Geophysics and Ceramic Science, Oxford University Press, New York, 1995] and the extrapolated data reported by Singh and Chauhan [Physica B 315 (2002) 74]. It is found that the relationship proposed by Singh et al. [Physica B 349 (2004) 401] for thermal expansivity and isothermal bulk modulus also holds well for other elastic moduli such as C11,C44,CS and KS.