Influence of Surface Modification and Dispersive Additives on Dielectric and Electrical Properties of BiFeO3/Poly(methyl methacrylate) Composite Films

Abstract

Surface modification plays an important role to enhance the dielectric constant and minimize the dielectric loss. In this study, poly(methyl methacrylate) (PMMA) composites filled with 2-aminoethanesulfonic acid-modified bismuth ferrite (BiFeO3; BFO) have been prepared via solution casting technique. The surface morphology of the composites provides a better homogeneous dispersion of the particles in the polymer matrix and increases interface compatibility between modified BFO and PMMA matrix. The experimental results show that the composites have high dielectric constant (≈ 147), alternating current (AC) conductivity (1 × 10−5) and relatively low loss (< 1) at 100 Hz. The percolation phenomenon is well observed in the composite having less than 30 wt.% of BFO particles. Further, the composites produce passivation layers on the surface of modified BFO particles which might improve the morphology and promote the space charges, interface effects and dielectric properties. Our strategy is to provide a simple and efficient approach to fabricate high-performance dielectric composites for energy storage applications.