Study on Synthesis and Properties of the Hafnium Tungstate by CO2 Laser

The crystal structure of hafnium tungstate 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 hafnium tungstate blocks are rapid synthesized by CO2 laser. The result of XRD and Raman spectra show that the samples contain single cubic phase of α-HfW2O8 with space group P213. The SEM observations show that the sample is composed of nano-rods which grow horizontally on the surface and in the interior. The nano-threads in the interior are composed of densely packed nano-crystallites.