A prediction model of thermal expansion coefficient for cubic inorganic crystals by the bond valence model

ABSTRACT On the basis of the bond valence model, a new prediction model of thermal expansion coefficient for cubic inorganic crystals using a simple formula is presented. The bond linear thermal expansion coefficient is introduced as a parameter deduced by bond valence and bond length, and can directly describe the thermal expansion of chemical bonds. For cubic multibond crystal systems, the linear thermal expansion coefficient can be obtained by an average of the linear thermal expansion coefficients of all constituted binary systems. Our model has been applied to well predict typical cubic ANB8-N, AmBn, and multibond crystals with spinel, garnet, pyrochlore, chalcopyrite, and perovskite type structures. The empirical model can offer a simple and reliable thermal expansion prediction by the bond linear thermal expansion coefficients and structure parameters based on the well-described nature of chemical bonding, which makes it powerful for exploring materials with potential applications related to thermal expansion.