以化学计量比的硝酸钡、硝酸铁和柠檬酸为原料采用溶胶-凝胶工艺制备M型钡铁氧体纳米粉体,通过XRD、TEM等测试手段表征粉体的结晶特性及微观结构,并研究反应机理以及烧结温度、保温时间对晶粒尺寸的影响,结果表明:粉体的平均晶粒尺寸为40-70 nm,烧结温度显著影响结晶过程、晶粒尺寸及其分布;烧结温度为800℃,保温时间为0.5 h的条件下形成的粉体颗粒呈棒状,棒的长度约为150-200 nm,直径约为30-50 nm。
M-type barium ferrite (BaFe12O19) nanopowders were synthesized by a sol-gel process. The crystalline properties and morphologies of the powders were characterized by means of X-ray diffraction (XRD) and transmission electron microscope (TEM). The reaction mechanism and the effects of calcinations temperature and calcinations time on grain size were studied. The results show that M-type barium ferrite powders with the average grain size range of 40-70 nm can be prepared at 800℃ and the calcinations temperature has obvious influence on crystalline process, the particle size and its distribution. The as-prepared samples obtained after heat-treatment at 800 ℃ for 0.5 h exhibit that the rod-like particles have a length of about 150-200 nm and a diameter of about 30-50 nm.