Electronic structure studies of chemically synthesized MgFe2O4 nanoparticles

• Confirmation of Fe3+ state in chemically synthesized MgF2O4 nanoparticles.
• Metal-oxygen hybridized states are influenced by crystallization growth.
• Crystallization growth affects cation inversion, oxygen parameter and bond lengths.

For present work, magnesium ferrite nanoparticles were synthesized using nitrates of metal ions and citric acid. Crystallite size of these nanoparticles varies from 2.1 ± 0.1 to 62 ± 10 nm as annealing temperatures increases from 300 to 1200 °C. Mg K-edge near-edge X-ray absorption fine-structure spectra reflect the presence of Mg2+ ions in both tetrahedral (A-site) and octahedral (B-site) environment for nanoparticles synthesized at all temperatures. The integral area of spectral features of O K-edge spectra is associated with the change of unoccupied O p-projected density of states. Fe L-edge spectra envisage the presence of Fe3+ state in these nanoparticles. Observed changes in the electronic structure of these nanoparticles are discussed on the basis of cation migration from A-site to B-site, degree of crystallization, and unsaturated bonds at crystallite surface. Fe–O distances at A-site and B-site changes with annealing temperature.

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