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.
出处
《稀土》
EI
CAS
CSCD
北大核心
1998年第5期33-36,共4页
Chinese Rare Earths
