Facile synthesis, characterization and magnetic property of CuFe_(12)O_(19) nanostructures via a sol-gel auto-combustion process

摘要

Copper hexaferrite (CuFe_(12)O_(19)) nanostructures were prepared by a simple route utilizing maltose-assisted sol-gel process. The morphology, phase structure, composition and purity of nanostructures can be controlled by type of surfactant and also adjusting the Cu:surfactant, Cu:Fe and Cu:reductant ratios. The bean-shape structures are formed in the absence of the surfactant when the molar ratio of Cu:Fe and Cu:reductant are 1:12 and 1:26, respectively. The agglomerated spherical nanoparticles with diameters ranging from 7 to 20 nm are obtained in the presence of triplex, when ratio of Cu:reductant is 1:26. In the absence of surfactant and also in the presence of triplex, the samples are found to be CuFe_(12)O_(19). When polymer is used, there are still the peaks of CuFe_(12)O_(19) and also some boad peaks in XRD patterns, because of the small size and encapsulation of nanostructures with polymer. Magnetic measurments show su-perparamagnetic behavior for the all samples. The M_s for the samples obtained in the presence of polymer shows that the coating of magnetic nanostructures does not always increase M_s. FT-IR frequency bands in the range 463-626, 607 and 542 cm~(-1) correspond to the formation of metal oxides in ferrites.