Tailoring dielectric properties of flexible ceramic sheets through graphene doping in the diatomite matrix

Abstract

This work presents a novel tape-casting method for producing flexible, graphene-enhanced diatomite ceramic sheets. These sheets target dielectric substrates for applications in the critical yet under-explored, high-frequency range. Structural and morphological analyses confirmed the incorporation of graphene nanoplatelets into the ceramics matrix, validating the efficiency of the tape-casting process. The results show the crucial role of the composite's crystalline structure in its dielectric response, where oxygenated functional groups within the graphene nanoplatelets act as intrinsic barriers to restrict leakage current, resulting in low dielectric loss. Doping of flexible ceramic plates with graphene nanoplatelets led to significant dielectric variations of approximately 100% over a wide frequency range. The capacitance increased by 215.35$\%$ with the addition of 10 wt.$\%$ graphene compared to pure diatomite. Our results demonstrate the ability to adapt the framework's structural, morphological, and dielectric properties through doping with graphene in diatomite, offering promising prospects for applying flexible ceramic sheets at high frequency.