负热膨胀材料立方ZrMo_2O_8合成研究

Synthesis of Negative Thermal Expansion Material Cubic ZrMo_2O_8

采用湿化学法合成了前驱物ZrMo2O7(OH)2(H2O)2,并用SEM观察了不同回流时间所得晶粒形貌,结果显示经过较短时间的回流(12h)就能获得一定尺寸的晶粒并趋于稳定。观察了不同回流温度所得前驱物晶粒形貌,其晶粒呈长方体棒状形态,XRD结果证明结晶度随回流温度的升高而提高;探讨了不同回流温度下所获得的前驱物ZrMo2O7(OH)2(H2O)2对合成立方ZrMo2O8的影响。结果表明,100℃回流所得前驱物经热处理后可获得纯立方相ZrMo2O8。此外,对前驱物的热处理温度选择在400℃左右有利于纯立方相的获得。

ZrMo_2O_7(OH)_2(H_2O)_2 is synthesized by using a chemical route. SEM is used to observe the morphology of precursors obtained by refluxing for various time. The results show that after refluxing for 12 h stable crystal grains are obtained. Morphology of precursors is observed mainly as rod-like particles. XRD results prove that the higher crystalline precursor is obtained with a higher refluxing temperature. The influence of refluxing temperature on the synthesis of cubic ZrMo_2O_8 is discussed. The results demonstrate pure cubic ZrMo_2O_8 is synthesized after heat-treatment of precursor refluxing at 100 ℃. Besides, heat-treatment at 400 ℃ is favorable to the synthesis of pure cubic phase.