Effect of Rare Earth (La³⁺) on the Structural, Microstructural, and Transport Properties of CoCr₂O₄ for Industrial Applications

In the category of oxides, spinel oxides can be identified by their chemical formula. Spinel oxides have the structure AB₂O₄ and are distinguished by their amazing magnetic, electric, and multiferroic properties. Additionally, they exhibit a wide variety of functional responses. A description of the experimental, structural, and electrical properties of Co_1–xLa_xCr₂O₄ (where x = 0 and 0.05) was presented in this study for the very first time. During the course of the experimental characterization, data on AC conductivity and dielectric parameters, as well as XRD and SEM micrographs, were collected. It was demonstrated beyond a reasonable doubt that a spinel cubic structure is produced by the XRD characteristics of each sample. The scanning electron micrographs (SEM) showed that every single one of the samples is very porous. An overall increasing trend of the dielectric constant was seen in the La³⁺ doped CoCr₂O₄ sample as the concentration of La³⁺ increased. This is a result of the probable hopping of Cr²⁺ to Cr³⁺, as well as an increase in the average crystallite size with La doping. Koop’s phenomenological theory was utilized in order to provide an explanation for the AC conductivity, and the hopping process was utilized in order to characterize the electrical properties of each sample. All of the samples exhibited outstanding alternating current conductivity and a low dielectric loss tangent at higher frequency ranges throughout the whole spectrum.