Influence of chromium doping on structural, microstructure, optical and electrical properties of zinc ferrite.

Abstract Zinc ferrite with crystalline nature with the formula ZnFe2-xCrxO4, (x =0.0 to 0.4, in the step of 0.1) were produced utilizing a sol-gel auto-combustion approach taking Glycine (C2H5NO2) as a chelating agent and annealed at 800°C for 5h. XRD analysis revealed the presence of α-Fe2O3 as an extra peak. The lattice parameter reduces from 8.4423 Å to 8.4191 Å as the chromium content increases. The FTIR spectroscopy results exhibit two significant absorption bands approximately at 400 cm⁻¹ and 600 cm⁻¹ Indicating the successful formation of the spinel crystal structure in the synthesized sample. Debye temperature elevated from 670.95 K to 696.15 K with Cr3+ doping. Elastic constants also increase with Cr3+ doping. The band gap energy, determined using Tauc plots, varies between 2.05 eV to 2.25 eV. The DC resistivity plot exhibited semiconducting behavior. Resistivity increases with Cr3+ doping concentration. A linear inverse correlation was observed between the Curie temperature and the concentration of Cr3+ ions. With increasing chromium content, the activation energy (ΔE) exhibited a positive trend from 0.26 eV to 0.39 eV, while the charge carrier concentration (n), drift mobility (µd), and diffusion coefficient (D) demonstrated inverse relationships. The obtained structural, elastic, optical and DC electrical data is useful for high-frequency device applications.