Thermal expansion of ionic materials at high temperatures

A simple and straightforward method for evaluating and predicting the high temperature volume thermal expansion of ionic materials is developed based on the approximations that at high temperature the temperature derivative of the work done by thermal pressure approaches a constant and the isothermal bulk modulus is linearly dependent on temperature. The reasonableness of the two approximations is strongly supported by the investigations presented by Wang and Reeber [e.g., J. Mater. Res. 11, 1800 (1996); High Temp. Mater. Sci. 35, 181 (1996)]. The tests on NaCl, KCl, MgO, and CaO demonstrate that the agreement between the calculated results obtained from the present method and the corresponding experimental data are very good.