Abstract
This study investigated the thermal, structural, and optoelectronic properties of Mg0.4Cu0.4Cd0.2Cr2O4 spinel chromites prepared by the sol-gel method at different calcination temperatures (850 and 950 degrees C). According to Rietveld's refinement of the X-ray patterns, the samples crystallized in the cubic spinel structure (Fd3m space group). As the calcination temperature increases, crystallite size and unit cell parameters increase. The FTIR bands of the tetrahedral (A) and octahedral [B] sites shift toward higher wavenumbers with the rise of calcination temperature. From the absorbance and Tauc method, the samples exhibit direct optical transitions. The band-gap energy (Eg) decreases due to the increase in crystallite size. Urbach energies also decrease, implying a decrease in defects and disorders with increasing calcination temperature. In addition, penetration depth, refractive index, extinction coefficient, dielectric constants, conductivity, and loss factor were studied versus wavelength. From these variations in optical parameters, some interesting optoelectronic applications were derived for the as-synthetized Mg0.4Cu0.4Cd0.2Cr2O4 samples.