Grain boundary engineering that induces ultrahigh permittivity and decreased dielectric loss in CdCu ₃ Ti ₄ O ₁₂ ceramics

Abstract

Abstract Dielectric materials with ultrahigh permittivity are attracting attention due to the increasing demand for these types of materials for microelectronics and energy storage applications. In this work, we successfully synthesized Zn‐doped CdCu 3 Ti 4 O 12 (CdCTO) ceramics with low dielectric loss and large permittivity via an ordinary mixed‐oxide technique. Remarkably, at a Zn doping level of 0.10, a CdCu 2.9 Zn 0.1 Ti 4 O 12 ceramic exhibited both decreased dielectric loss tangent of ~0.058 and large dielectric permittivity > 4.0 × 10 4 , as well as a good frequency stability over a wide frequency range from 40 Hz to 10 6 Hz. The high dielectric performance was attributed to the enhanced grain boundary resistance and internal barrier layer capacitor (IBLC) effect due to the fine and uniform grains that formed upon Zn doping. The findings reported in this work provide valuable insights into how to simultaneously realize a low dielectric loss and high permittivity in CdCTO and other related dielectric ceramics.