Glycine-assisted fabrication of nanocrystalline cobalt ferrite system

摘要

Nanoparticles of CoFe_2O_4 are synthesised by combustion method employing glycine or a mixture of glycine and ammonium nitrate as fuels with corresponding metal nitrates. The as-prepared powders are nanosized and this result is confirmed by IR, XRD, scanning electron micrograph (SEM) and transmission electron micrograph (TEM) techniques. When glycine alone is used as fuel, nanosized CoFe_2O_4 phase is formed with CoO being in the moderate crystalline state. When the mixture of glycine and ammonium nitrate is used, well-crystalline CoFe_2O_4 is obtained as a single phase. Thus, combustion synthesis using mixture of glycine and ammonium nitrate is proposed to be a route to stabilise CoFe_2O_4 crystallites. Both the saturation magnetization (M_s) and the remnant magnetization (M_r) were found to be highly depending upon the size and crystallinity of the investigated ferrite. The highest coercivity (820 Oe) was achieved by the sample containing a mixture of glycine and ammonium nitrate. Our results indicate that this method might provide a promising option for synthesizing high-quality CoFe_2O_4 nanopowder.