Very Low Loss Tangent and High Dielectric Permittivity in Pure‐ CaCu ₃ Ti ₄ O ₁₂ Ceramics Prepared by a Modified Sol‐Gel Process

We present a simple strategy to achieve excellent dielectric and nonlinear current–voltage properties for pure– CaCu 3 Ti 4 O 12 ceramics prepared by a modified sol–gel method with different calcining conditions. At 1 kHz and room temperature, the best CCTO ceramic can exhibit a high dielectric constant (ε′) of 9516 with a very low dielectric loss, tan δ ~0.020. The minimum value of tan δ is 0.018 at 2.5 kHz with ε′ ~9433. High breakdown field of 4032 V/cm and nonlinear coefficient of 7.05 were obtained.