柠檬酸用量对制备纳米晶CaMnO_3粉末的影响

Effects of citric acid ratio on nanosized crystalline CaMnO_3 powder

柠檬酸的用量将影响CaMnO3粉末性能。以金属硝酸盐为原料，去离子水和乙二醇为溶剂，在不同柠檬酸络合剂用量的情况下，采用溶胶凝胶法制备了CaMnO3溶胶。通过煅烧干凝胶前驱物制得了钙钛矿型CaMnO3多晶粉末。利用X射线衍射仪、扫描电子显微镜、激光粒度分析仪等手段分析了所得粉末。结果表明：所得钙钛矿型CaMnO3晶粒度在20-50nm之间，粉末为300500nm多边形颗粒，粒度随柠檬酸用量增加而增大，晶粒尺寸也逐渐增大，增幅均较小。

Molar concentration ratios of citric acid to Ca^2＋ affect properties of CaMnO3 powders. In this paper, CaMnO3 gel was prepared through the sol gel method veith deionized water and ethylene glycol as solvent, different ratios of citric acid as che- late, and metal nitrates as starting materials. Perovskite polycrystalline CaMnOa powders were prepared via calcining the dry gel, and were analyzed with XRD, SEM and Marlvern granularity analyzer. The results show that the crystal size ranges from 20 to 50 nm, and the resulting perovskite CaMnOa powders are flat-shaped granules of about 300-500 nm. The granularity and crystal size of the CaMnO3 powders increase slightly with the increase of the molar concentration ratio.