EPR and optical studies of pure MgFe₂O₄ and ZnO nanoparticles and MgFe₂O₄–ZnO nanocomposite

A comprehensive EPR and optical studies of pure MgFe₂O₄ and ZnO nanoparticles and MgFe₂O₄–ZnO nanocomposite have been done in order to explore its future possibilities of applications. Pure MgFe₂O₄ and ZnO nanoparticles have been synthesized using Sol–Gel method. MgFe₂O₄–ZnO nanocomposite has been prepared using water dispersed pure MgFe₂O₄ nano seeds (previously synthesized) by ultrasonication. Effect of introducing zinc oxide in pure MgFe₂O₄ nanomatrix on structural properties was investigated using X-ray diffraction and transmission electron microscopy techniques. They confirm the cubic spinel structure of both pure and ZnO imbedded MgFe₂O₄ samples. UV–Visible and photoluminescence spectra show that the band gap of composite is tuned and more useful for photocatalytic applications. FTIR spectra indicate the presence of absorption bands in the range 390–561 cm⁻¹, which is a common feature of spinel ferrite. The energy dispersive spectroscopy analysis confirms the composition of specimen. Further, the investigation of electronic and magnetic properties of the powdered samples is done using electron paramagnetic resonance spectroscopy. Change in g value, peak-to-peak line width (H_pp), resonance field (H_r) and spin–spin relaxation time (T₂) give useful information.