Crystal Structure of ZrW2O8 and the Intermediate Products Prepared with Coprecipitation Method

Negative thermal expansion zirconium tungstate ZrW2O8 powder was prepared from ammonium metatungstate (NH4)10W12O41·5H2O and zirconium oxychloride ZrOCl2·8H2O with coprecipitation method. The physical structure of the precursor,intermediate powder in the synthesis and final product powder were analyzed by X-ray diffraction,and XRD data of ZrW2O8 crystal structure were treated by FullProf-Suite software and Material Studio software,in which the atomic coordinate parameter and the crystal structure parameter of ZrW2O8 were refined. The results indicated that the structure of precursor was identified as amorphous,the crystallinity of the intermediate was 33.66%,and the final product was cubic phase ZrW2O8 with space group of P213(198),cell parameter of 0.915 98 nm and cell volume of 0.768 52 nm3. Through XRD data treatment it was obtained that the figure of merit for the index F(30) was 57.1(44),the peak profile simulation factor RP was 0.251 9 and the weight factor Rwp was 0.134 3.