Fe-Al oxide composite magnetic nanoparticles synthesized by sol-gel method

Fe-Al oxide magnetic composite nanoparticles were synthesized by sol-gel technique.The multiphase Fe-Al oxide crystallinity of the composite magnetic particles was characterized with X-ray diffraction.The results showed that the larger the mass ratio of Fe to Al2O3,the better the magnetism of the sample under the same heat treated temperature.While for fixed mass ratio of Fe to Al2O3,lower heat treated temperature is favorable to the formation of Fe3O4 phase,which leads to the sample with better magnetism.Among all samples in our experiments,the maximum saturation magnetization(21.1 A·m2/kg) was obtained for the sample with Fe Al2O3=3∶1(mass ratio) and heat treated at 300℃.However,the maximum coercive force(187.2 mT) was obtained for the same sample heat treated at 900℃.