ZrW_(2-x)Mo_xO_8的合成、表征与热膨胀特性

Synthesis and Characteristics and Properties of ZrW_(2-x)Mo_xO_8

立方结构的ZrW2-xMoxO8氧化物材料具有各向同性负热膨胀效应,但难以用固相化学反应法制备.采用水热法合成了Zr(W,Mo)2O7(OH)2(H2O)2,热重-差热分析(TG-DTA)表明,Zr(W,Mo)2O7(OH)2(H2O)2的DTA曲线上有明显的ZrW2-xMoxO8结晶转变点,且结晶点随Mo含量的增加而降低.严格控制加热工艺条件,将Zr(W,Mo)2O7(OH)2(H2O)2作为前驱体低温合成了ZrW2-xMoxO8系列氧化物材料,高温X射线衍射分析表明ZrW2-xMoxO8具有强烈的负热膨胀效应.

ZrW2-xMoxO8 with cubic structure has the isotropic negative thermal expansion properties,but it is difficult to synthesize by using solid state reaction. Using the hydro-thermal method,Zr(W,Mo)2O7(OH)2(H2O)2 is prepared. The thermogravimetric and differential thermal analysis (TG-DTA) is employed to determine the transition of ZrW2-xMoxO8, and the results show the crystalline temperature of ZrW2_xMxO8 decreases with the x value growth.The cubic ZrW2-xMoxO8 is synthesized under controlled heat treatment conditions with Zr(W, Mo)2O7(OH)2(H2O)2 as a precursor.X-ray results show the cubic ZrW2-xMoxO8 exhibits negative thermal expansion in the measured temperature range.