Continuous production of γ-Fe_2O_3 ultrafine powders by laser pyrolysis

摘要

Pure γ-Fe_2O_3 particles were prepared by a continuous process from cw CO_2 laser induced pyrolysis of a 30/100 solution of iron pentacarbonly in isopropanol with a yield of about 50/100 and an average productivity of 0.05 g/h. From TEM the particle size is 5±2 nm with a low degree of aggregation, which agrees with the size obtained from the width of the X-ray diffraction peaks. The nanoparticles seem to be well crystallised according to his infrared spectrum. Moreover, superparam- agnetic behaviour was observed at room temperature with a saturation magnetisation value of 30.5 emu/g.