Dielectric property optimization of polymer nanocomposites using BaTiO3 based high-entropy ceramic filler with Dirac-cone effect

BaTiO 3 (BTO) based nanoceramics play an important role in electronic devices. Here, we synthesized three BTO-based high-entropy nanoceramics and calculated their band gaps via density functional theory (DFT). Firstly, cubic high-entropy ceramic powders, namely (La 0.2 Ca 0.2 Sr 0.2 Ba 0.2 Li 0.2 )TiO 3 , Ba(Ti 0.2 Sn 0.2 Zr 0.2 Hf 0.2 Nb 0.2 )O 3 and Ba(Ti 0.2 Sn 0.2 Hf 0.2 Zr 0.2 Ta 0.2 )O 3 , were synthesized. Then, composition and morphology of powders was determined. Ultimately, their band gaps were calculated. We clarified the influence of metal co-doping on band gaps. Dirac-cone band-structure was found in Ba(Ti 0.2 Sn 0.2 Zr 0.2 Hf 0.2 Nb 0.2 )O 3 . Compared with BTO (band gap 1.821 eV), BTO-based high-entropy ceramics can have the reduced band gaps (1.549 eV; 0.001 eV; 0 eV) using various co-doping. By high-entropy strategy, conductive ability of BTO-based ceramic is regulated. Experimental results of polymer/ceramic composite dielectrics and theoretical results of ceramics are consistent. Dirac-cone ceramic filler is promising for preparing polymer-based composites for energy storage. This research enables mass preparation of high-entropy ceramic/polymer dielectric composites.