Effect of calcinations on the structural and magnetic properties of magnesium ferrite nanoparticles prepared by sol gel method

Magnesium ferrite nanoparticles calcined at 300 °C, 350 °C, 400 °C, 450 °C were synthesized by sol-gel method. The effects of calcinations on the cation distribution, structural and magnetic properties have been investigated. X-ray diffraction (XRD) and vibrating scanning magnetometer (VSM) were used to characterize the structural and magnetic properties. X-ray diffraction analysis revealed the formation of single phase MgFe2O4 in all the samples. Lattice constant and crystallite size increased with calcination. X-ray diffraction data were used to estimate the average cationic distribution among A site and B site. Cationic distribution shows that there is migration of cation between tetrahedral A site and octahedral B site. Saturation magnetization increased with particle size. Coercivity decreased with calcination temperature as a result of decrease in pinning effect at the grain boundary. Curie temperature (TC) decreased slightly due to weakening of A-B exchange interaction. Low temperature magnetic measurement revealed that blocking temperature (TB) increased due to strong magnetic interaction.