Microwave Combustion Synthesis of Silver Doped Lanthanum Ferrite Magnetic Nanoparticles

Lanthanum ferrite (LaFeO3) and silver doped LaFeO3 powders were synthesized by a single step microwave combustion route using nitrates as precursors and glycine as a fuel. XRD analysis indicated the formation of cubic phase with the dopant peaks at 20 values of 38.3 degrees, 44.1 degrees, and 64.4 degrees apart from the peaks corresponding to LaFeO3. As observed from the transmission electron micrographs, LaFeO3 exhibits particles with a larger size (mean size 57 nm), significant decrease in particle size is observed for silver doped samples. The magnetic measurements reveal weak ferromagnetic nature of LaFeO3, while silver doped samples are ferromagnetic in nature. Lanthanum silver ferrite (x = 0.25, A site) shows maximum coercivity (Hci = 480.96 G) with hysteresis loop at room temperature which is a clear sign of ferromagnetic ordering. The S shape of the curve implies the presence of domain wall movements in nanoparticles. Thermogravimetric analysis of the samples show stable behavior of the products.