Research on the Al³⁺，V⁵⁺ Double Ionic Substitute Negative Thermal Expansion Compound Zr_1-xAl_xMoW_1-yV_yO₈

Abstract

The ZrW2O8 family of materials has been shown to display the unusual property of an isotropic bulk contraction in volume with the rising of temperature. They have a number of potential applications, for example, they would be widely used in composite material and solid electrolyte based on its characteristic of negative thermal expansion and ionic conductive property. In this paper, an Al3+，V5+ double substitute negative thermal expansion (NTE) solid solution Zr1-xAlxMoW1-yVyO8 was synthesized by co-precipitation method. The phase composition, the micromorphology and the thermal expansion coefficient were obtained by using X-ray diffraction (XRD), scanning electronic microscope (SEM) and thermal mechanical analyzer (TMA), respectively. The results show that the sample’s density rises with the increasing of the content of V5+, while, its porosity declines. The thermal expansion coefficients of the samples are between -3.0~4.0×10-6 K-1, it indicates that their negative thermal expansion behavior is a little lower than that of ZrMoWO8. And the experiment also shows that these samples have displayed a fine behavior of heat shock resistance.