Investigating the structural and dielectric properties of CoFe2-xNixO4 spinel ferrite

The present work reports the structural and dielectric properties of pristine and Ni-doped spinel CoFe2O4. To investigate the influence of doping on the structural and dielectric properties of the samples, the samples were synthesized using a solid-state reaction approach. A single-phase FCC cubic spinel structure with space group Fd3 over bar m was confirmed for all the prepared materials with the help of Rietveld refinement. The cationic distribution indicates a decrease in the occupancy of Fe2+ and the corresponding increase of that of Ni2+. The microstructural analysis and the elemental composition analysis was carried out using SEM and energy dispersive spectroscopy (EDS) respectively. For all samples the temperature-dependent dielectric characteristics were investigated, revealing the presence of orientational and interfacial polarization. The dielectric constant is temperature independent until it reaches around 270 K, after which it begins to increase with increasing temperature. And this temperature starts decreasing for higher doping concentrations. Also, CoFe1.9Ni0.9O4. was seen to have strong relaxation behavior and low dielectric loss. The low dielectric loss of CoFe1.9Ni0.9O4 makes it useful at higher frequencies in electrical circuits that faces the challenges of high-temperature rise.

Automated summary

This study investigates the structural and dielectric properties of pristine and Ni-doped spinel CoFe2O4. The samples were synthesized using a solid-state reaction approach, and the structural analysis confirmed a single-phase FCC cubic spinel structure. The cationic distribution revealed changes in occupancy due to doping. SEM and EDS were used for microstructural and elemental composition analysis. The study found the presence of orientational and interfacial polarization in the samples. The dielectric constant showed a temperature-dependent behavior, with an increase observed after reaching a certain temperature. CoFe1.9Ni0.9O4 exhibited low dielectric loss and strong relaxation behavior.