摘要
用透射电镜和图像分析仪等研究了超细铁粉和γ-Fe_2O_3粉末的结构、形貌、粒子的平均尺寸以及粒度分布。研究结果表明,多数超细铁粉粒子近似呈球形,并且,铁粉粒子由两相组成,粒子的核心部分是金屑a-Fe,表面的包裹层为氧化物层,它由Fe_3O_4和7-Fe_O_3的混合物组成。氧化层的平均厚度大约占整个粒子直径的20％左右。羰基铁粉粒子(含氧化层)的平均直径为16nm。直径在4～24nm范围的粒子数占总粒子数的91％,而7-Fe_2O_3粉末既有雪茄状粒子,也有小球状粒子。分析表明,球状粒子的平均直径为113nm,雪茄状粒子的平均直径(按<长+宽>/2计算)为148nm。由于超细铁粉粒子很细,且有磁性,制备电镜试样时分散比较困难。本文比较了几种分散方法后,使用了一种较好的分散方法——超声喷管分散法。
The structure,the shape,the average size of particles and the distribution of size of both ultrafine Fe powder and r-Fe_2O_3 powder have been investigated with TEM and Image-analyzer. The results show that most of the ultrafine Fe particles are almost round and the Fe powder is composed of two phases. The core of Fe particle is α-Fe and it is wrapped by the oxide which is the mixture of Fe_3O_4 and r-Fe_2O_3. The thickness of the oxide layer takes up about 20% of the diameter of the whole particle. The average diameter of Fe powder particles (including oxide layer) is 16nm. The particles with 4nm to 24nm in diameter take up 91% of the whole number of particles. Some of the 7-Fe_2O_3 particles are in the shape of cigar and others are round. The analyses indicate that average diameter of round particles of r-Fe_2O_3 is 113nm and the average diameter of particles in shape of cigar is 148nm (according to the formu-lar:diameter=(length+width)/2). Because the Fe particles are too small and have magnetism,it is difficult to disperse them when the TEM specimens are prepared. So several dispersing methods were compared and then we used the best way, ultrasonic spraying dispersion, to prepare the TEM specimens.
出处
《理化检验（物理分册）》
CAS
1994年第3期17-20,27,共5页
Physical Testing and Chemical Analysis(Part A:Physical Testing)
关键词
超细铁粉
氧化铁粉
粉末粒度
铁粉
Ultrafine iron powder, Iron oxide powder, Nanocrystalline material, Powder Size
