Tuning of dielectric and magnetic performance of graphene oxide via defect regulation by metal oxide nanoparticle for high temperature device

Abstract

Graphene oxide (GO) is used as a dielectric material in device applications. However, relatively low dielectric constant, high loss, and low working temperature significantly constrain their widespread application. The electrical and magnetic properties of GO can be regulated by using different fillers. Here, we try to regulate the defects of Zinc Oxide ( ZnO) by doping Fe ions and then make composites with GO (GO@ZnO-Fe) towards the increment of the dielectric constant and reduce the loss of GO. The morphology and microstructure characterization of GO composites ensured the enhancement of interlayer cross-links and lateral bridging between the edges of adjacent GO sheets in the presence of ZnO and ZnO-Fe nanofillers. The layered structure of GO produced charge accumulation based on the Maxwell- Wagner (MW) polarization, and after compositing, with ZnO nanofillers, the dielectric constant of GO increases from 350 to 470. But the use of Fe doped ZnO nanofiller increased the maximum dielectric constant to∼ 2240 due to the synergic effect of ZnO and Fe ions. At the same time, the loss is also decreased simultaneously with increasing Fe doping (tanδ =96 for GO and 30 for composite). The dielectric surge occurs at different high temperatures for different composites of GO, and before the surge, the dielectric constants are thermally stable. The conductivity and magnetic properties of the composites increases compared to GO due to the presence of Fe2+/Fe3+ ions. The increase of Fe doping composites displayed thermally stable dielectric properties with a high dielectric constant (7100) and low loss over a broad temperature. Our work demonstrates an efficient method of tuning the dielectric, conductive and magnetic properties of GO-based materials that hold great potential in high-temperature electronic applications.