Magnetic and optical properties of zinc chromite nanostructures prepared by microwave method

The nanostructures of zinc chromite (ZnCr2O4) were fabricated by the microwave method. It was shown that the well-crystallized spinel structure is formed after annealing at 700 °C. The influence of reaction time and irradiation power of oven on the size and shape of the as-prepared ZnCr2O4 samples was studied. The synthesized samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray (EDX), transmission electron microscopy (TEM), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) spectroscopy, Fourier transform infrared (FTIR) spectra and vibrating sample magnetometry (VSM), respectively. The optical band gap calculated using DRS was found to be 3.50 eV for ZnCr2O4 nanostructures. Photoluminescence measurements also confirmed this result.