机构地区: 南昌大学
出 处: 《稀土》 1998年第5期33-36,共4页
摘 要: 采用溶胶—凝胶工艺制备了纳米晶氧化物Dy1-xSrxCoO3-y,并对其低温形成机理进行了研究,结果表明:100~200℃柠檬酸配体变化不大;300℃时配合物已开始分解,生成了单齿碳酸盐,同时形成了SrCoO3-y晶相骨架;400℃晶化过程出现微区不均匀性;一级相变吉布斯自由能一阶偏微熵的改变,体现为结晶放热过程,整个晶化过程处于一种氧缺陷状态;700℃时已形成纳米晶氧化物Dy1-xSrxCoO3-y,低于传统的合成温度。 Nanocrystalline Dy 1-x Sr xCoO 3-y (x=0 6) had been prepared by means of sol-gel technology,and its low-temperature formation process was studied.The results show that the complex structure of citric acid has a little variation at 100℃.The complexes of citric acid had been decomposed and yielded single ligand carbonate,meantime it formed crystal skeleton of SrCoO 3-y at 300℃.The process of crystallization appeared as microheterogeneity at 400℃,and the variation of Gibbs free energy of first order phase transition embodied crystallo-exothermic process.All process of crystallization was in oxygen defect state.The nanocrystalline Dy 1-x Sr xCoO 3-y had been synthesised at 700℃,and the formation temperature of perovskite oxides was 1300℃ by conventional solid phase reaction method.