化学学报 ›› 1998, Vol. 56 ›› Issue (8): 780-784. 上一篇    下一篇

研究论文

纳晶稀土复合氧化物Dy~1~-~xSr~xCoO~3~-~yⅡ: 固相烧结动力学研究

魏坤;彭珊珊;石燕   

  1. 南昌大学稀土工程中心食品科学与工程系
  • 发布日期:1998-08-15

Nanocrystalline rare earth mixed oxides Dy~1~-~xSr~xCoO~3~-~yⅡ: Study on the solid state sintering kinetics

WEI KUN;PENG SHANSHAN;SHI YAN   

  • Published:1998-08-15

研究了纳晶氧化物Dy~1~-~xSr~xCoO~3~-~y(x=0.6)的等温烧结动力学,计算了烧结激活能, 结果表明: 在烧结初期, 致密化机制主要为蒸发-凝聚传质; 在烧结中期, 致密化机制转为晶界控制。烧结过程的激活能为5.255×10^4J·mol^-^1。较小的激活能体现了纳米粒子的尺寸效应。快速运动的晶界, 导致晶界与气孔的运动速度不匹配, 造成纳晶氧化物密度低, 最终形成纳米海绵态网络结构。

关键词: 等温, 固相烧结, 复合物, 动力学研究, 致密化, 稀土氧化物, 尺度效应, 纳米材料, 锶氧化物, 钴氧化物

The isothermal sintering kinetics of nanocrystalline Dy~1~-~xSr~xCoO~3~-~y (x=0.6) were studied, and the sintering activation energy was calculated. The results show that the main densification mechanism is evaporation-condensation mechanism and grain boundaries control mechanism in during the initial and middle sintering stage respectively. The sintering activation energy of Dy~1~-~xSr~xCoO~3~-~y is 5.255×10^4 J·mol^-^1. It appeared as nanometer size effect. The grain boundaries with fast moving resulted in dismatching between grain boundaries and pores moving velocity and the density of nanocrystalline oxides was low. Finally, it formed network structure nanometer sponge state.

Key words: ISOTHERMALS, SOLID-PHASES SINTERING, COMPLEX, KINETIC STUDY, DENSIFYING, RARE EARTH OXIDE, SCALE EFFECT, NANOMETER MATERIALS

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