Synthesis, dielectric, and magneto – dielectric properties of carbon quantum dots/ZnFe2O4 hybrid nanocomposite

Abstract

Carbon quantum dots doped ZnFe2O4 Spinel Ferrite, that is, CQD-ZSF hybrid nanocomposite was thrivingly synthesised exploiting sol-gel based synthesis technique. Structural assessment supports Fd-3m space group with cubic spinel structure with mean size of 10.33 nm as obtained from Scherrer formula. Raman spectra confirmed the existence of CQD in ZSF. The samples contained a variety of vibration bands, according to the FT-IR analysis. The dielectric permittivity (ε) and tangent losses (tan δ) was conducted with frequency from 100 Hz to 1 MHz range at different temperatures ranging from 300 to 773 K. It was found that ε as well as tan δ receded monotonously with extending frequency. This information reveals a space or interfacial dipolar relaxation phenomenon. The electrical properties and the ion hopping dynamics were probed with the assistance of an AC-electrical conductivity (σac) analysis. Frequency-dependent σac heeded Jonscher’s law of power. The advent of arcs semicircular by nature in cole-cole plot indicates cloud of electronic process occurring within sample. At 300 K, by applying an external magnetic field varying till 1.5 Tesla magnetic field, the magneto-dielectric effects of the sample were measured by obtaining ε and tan δ versus frequency values displaying negative ML% (magneto-loss) and MD% (magneto-dielectric) coupling of −32.57% and −58.13%, respectively.