Enhanced dielectric response and non-Ohmic properties of Ge-doped CaTiO₃/CaCu₃Ti₄O₁₂

We present a method for increasing the dielectric constant of CaTiO3/CaCu3Ti4O12 (CTO/CCTO) composites and retaining low-loss tangent (tan?) by doping with Ge dopant. The Ge-doped CTO/CCTO were fabricated using one-step processing method. phase composition microstructure analyses confirmed existence CTO CCTO phases, in which ions can be substituted into both phases. mean grain sizes two phases slightly reduced decreasing porosity. Doping resulted high ~ times, while very low tan? value ~0.01 did not change. Furthermore, changed less than ±15% temperature range ?60 – 150°C. nonlinear current density–electric field properties also enhanced. Impedance spectroscopy showed heterogeneous enhanced boundary after dopants, giving rise to electrical properties. decreased resistivity due substitution is originate from increase Ti3+/Ti4+ ratio, was analyzed X–ray photoelectron .