Tailoring of thermal expansion and phase transition temperature of ZrW2O8 with phosphorus and enhancement of negative thermal expansion of ZrW1.5P0.5O7.75

Abstract

ZrW2O8 is a typical isotropic negative thermal expansion material with cubic structure. However, quenching preparation, pressure phase transition and metastable structure influence its practical applications. Adopting P to part-substitute W for ZrW2−x P x O8–0.5x has decreased the sintering temperature and avoided the quenching process. When x = 0.1, ZrW1.9P0.1O7.95 with a stable cubic structure can be obtained at 1150 °C. The thermal expansion coefficient is tailored with the P content, and phase transition temperature is lowered. When x = 0.5, thermal expansion coefficient attains −13.6 × 10−6 °C−1, ZrW1.5P0.5O7.75 exhibits enhance negative thermal expansion property. The difference of electronegativity leads to the decrease of phase transition temperature with the increase of P content. The different radii of ions lead to new structure of materials when P substitutes more. The results suggest that the P atom plays the stabilization role in the crystal structure of ZrW2−x P x O8–0.5x .