不同形貌ZrWMoO8粉体的制备、表征及其负热膨胀特性

采用水合前驱物分解的方法, 以钨酸铵、钼酸铵及硝酸氧锆为原料制备了不同形貌的ZrWMoO8粉体. 对其前驱体进行了热重-差热分析(TG-DSC), 并以X射线粉末衍射(XRD)、扫描电子显微镜(SEM)及X射线荧光光谱仪(XRF)等手段考察了不同胶凝剂(HCl, HClO4, HNO3, H2SO4及H3PO4)对产物结构和形貌的影响. 结果表明, 胶凝剂的选择对ZrWMoO8粉体的形貌有较大影响. 在100—700 ℃范围内, 以HCl为胶凝剂制备出来的立方相ZrWMoO8粉体的热膨胀系数为-3.84×10-6 K-1.

Preparation, Characterization and Negative Thermal Expansion Property of ZrWMoO8 Powders with Different Morphologies

ZrWMoO8 powders with different morphologies were obtained by using ammonium tungstate, molybdate tungstate and zirconium tungstate as the starting materials by dehydration of the precursor ZrWMoO7(OH)2(H2O)2. The precursor was studied by thermogravimetric and differential scanning calorimetry(TG-DSC). X-ray powder diffraction(XRD), scanning electron micrograph(SEM) and X-ray fluorescence spectrometer(XRF) were used to study the influence of the varieties of the gelling agents on the crystallization process and crystal morphology of the resulted products. The results show that the kinds of gelling agent has a great influence on the morphologies of the resulted products, the thermal expansion coefficients of cubic ZrWMoO8 prepared with HCl as the gelling agent is -3.84×10-6 K-1 from 100 ℃ to 700 ℃.