Core-shell like structured barium zirconium titanate-barium calcium titanate-poly(methyl methacrylate) nanocomposites for dielectric energy storage capacitors

Core-shell structured barium zirconium titanate-barium calcium titanate-poly(methyl methacrylate) [(Ba0.94Ca0.06)(Zr0.16Ti0.84)O3-PMMA] nanocomposites were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) of methyl methacrylate (MMA) from the surface of BZT-BCT nanoparticles. Polymer grafted BZT-BCT nanocomposite thick films (∼10 μm) have shown an improved dielectric constant (ε∼56), a high breakdown field strength (∼3 MV/cm) and high-energy storage density ∼22.5 J/cm3. The improved electrical properties of core-shell structured BZT-BCT-PMMA nanocomposites were attributed to improved nanoparticle dispersion and enhanced interfacial polarization due to the covalent linkage between polymer and nanoparticle interface. Mechanically stable and homogeneous composite films were obtained using the surface grafted BZT-BCT ceramic nanoparticles.133