Magnetic properties of lead ferrite nanoparticles prepared by the polymerized complex method

The lead ferrite (PbO·5Fe2O3) nanoparticles were prepared by the polymerized complex technique. Lead nitrate, iron nitrate hydrate, citric acid, and ethylene glycol were used as precursor materials. The thermal decomposition characteristics and crystallization behavior of the precursor were study by the thermogravimetric analysis (TGA) and X-ray diffraction. The phases of the nanoparticles can go from amorphous to spinel ferrite and hexagonal ferrite depending on the annealing temperatures. Single hexagonal ferrite phase nanoparticles with average particle size of 20.4 nm could be obtained through thermal decomposition of precursor at low temperature (600 °C). Magnetic force measurements of various particle sizes show that there is a Hopkinson transition peak at around 447–459 °C and this peak shifts toward higher temperature and becomes broader as the particle size decreases. Both the saturation magnetization and coercivity are strongly dependent on the particle sizes. The obtained hexagonal ferrite nanoparticles exhibit a soft magnetic feature with a low saturation magnetization.