Giant permittivity phenomena in layered BaTiO3–Ni composites

Abstract Layered BaTiO 3 –Ni cermet composites with a constant composition but diversified microstructures were produced by a rolling-and-folding processing method. These composites differ from conventional laminates in that their interface has a tendency to be wavy, with a globular or elongated second phase within a continuous matrix phase. Based on an analysis of the (di)electric properties and Monte Carlo simulations we confirmed the critical influence of the composite's microstructural characteristics on the percolation threshold. We found that the dielectric properties of the composite, when it is in the insulation regime, were controlled by the insulating BaTiO 3 phase. A giant effective permittivity of around 200 000, with modest losses of tan  δ