NiFe₂O₄纳米晶的合成及焙烧动力学

来源期刊：中南大学学报(自然科学版)2004年第3期

论文作者：杨华明 张向超 杨武国 黄承焕 邱冠周

文章页码：368 - 371

关键词：机械化学; NiFe₂O₄;纳米晶;焙烧;活化能

Key words：mechanochemistry; NiFe₂O₄; nanocrystallites; calcination; activation energy

摘    要：以α-Fe₂O₃和NiO粉体为原料,NaCl为稀释剂,利用固相机械化学反应,在高能球磨作用下合成了NiFe₂O₄纳米晶。采用X射线衍射分析了合成NiFe₂O₄的过程和不同焙烧温度对晶粒尺寸的影响,计算了前驱体热处理过程晶粒长大的活化能。研究结果表明:制备的NiFe₂O₄纳米晶的晶粒尺寸为20~30 nm;焙烧温度越高,晶粒尺寸越大; NiFe₂O₄晶粒长大的表观活化能为16.7 kJ/mol,这表明热处理过程的晶粒长大主要以界面扩散为主。

Abstract: Nanocrystalline nickel ferrite (NiFe₂O₄) was successfully synthesized by mechanochemical reaction of α- Fe₂O₃ and NiO powders in equimolar ratio with NaCl as a diluent through high energy balling. The reaction process and the effect of calcination temperature on the crystal size of the spinel NiFe₂O₄were discussed by X-ray diffraction(XRD) technique. The mechanism for the nanocrystallite growth was primarily investigated through the calculation of activation energy. The results show that synthesized NiFe₂O₄ has a nanocrystalline structure with a crystallite size of 20~30 nm. The higher the calcination temperature, the larger the crystallite size. The activation energy forthe crystal growth is evaluated to be 16.7 kJ/mol. It can be considered that the crystallite grows primarily by means of an interfacial reaction during the thermal treatment.

基金信息：国家自然科学基金资助项目