Rapid synthesis and Raman spectroscopic study of the negative thermal expansion material of A (WO_4)_2 (A = Zr~(2+), Hf~(2+))

摘要

The crystal structure of ZrW_2O_8 and HfW _2O_8 displays unusual property of isotropic negative thermal expansion in a wide temperature range, which brings about a number of important potential applications. In this work, densely packed A (WO _4)_2 (A = Zr~(2+), Hf~(2+)) are rapid synthesized by CO_2 laser. The result of XRD and Raman spectra show that the ZrW_2O_8 is γ phase with space group P2 _12_12_1 and HfW_2O_8 is α phase with space group P213. Due to the influence of compressive stress, laser rapid solidification technique is more suitable for industrial production of HfW_2O_8.