纳米氧化铁晶体生长动力学研究

Grain growth kinetics of nano-sized iron oxide

采用室温固相法制备前驱体Fe_2(C_2O_4)_3·5H_2O,考察了焙烧时间、焙烧温度及焙烧保温时间对纳米氧化铁晶粒的影响,并研究了氧化铁晶粒生长动力学。使用扫描电镜、傅里叶变换红外光谱仪和X射线衍射仪对前驱体和纳米氧化铁进行表征。结果表明,对比焙烧温度和焙烧时间的影响,焙烧保温时间对氧化铁纳米晶粒的粒径影响较大,是其最主要的影响因素。通过计算,草酸铁焙烧制备纳米氧化铁的晶粒生长平均激活能为279.46kJ/mol,纳米氧化铁的晶粒生长平均动力学指数n=18.24。

The room temperature solid phase method was used to prepare the precursor Fe2（C2O43· 5H2O for preparing the nano- sized iron oxide, and the effects of calcination time, temperature and its holding time on the crystals and the grain growth kinetics were investigated. The precursor and the nano-sized iron oxide were characterized by SEM, FrIR and XRD. The results show that the calcination temperature holding time has greater effect on the size of nano-sized iron oxide grain than the calcination temperature and time. In the ease of grain growth kinetics, the average activation energy is 279.46kJ/mol and the average kinetic index is 18.24.