Low dielectric loss, giant dielectric constant, and high breakdown electric field in (Bi1−xYx)2/3Cu3Ti4O12 ceramics

It is always a challenging problem to simultaneously obtain a large dielectric constant ( ɛ ′), low dielectric loss (tan δ ), and good nonlinear performance in the ACu 3 Ti 4 O 12 (ACTO) ceramic family. In this study, Y 3+ -doped Bi 2/3 Cu 3 Ti 4 O 12 ceramics with a giant ɛ ′, low tan δ , high breakdown field strength ( E b ), and high nonlinearity coefficient ( α ) were successfully prepared via the solid-state method. The (Bi 0.5 Y 0.5 ) 2/3 Cu 3 Ti 4 O 12 ceramic exhibited a huge ɛ ′ (∼12660), very small tan δ (∼0.019), high E b (∼15.7 kV/cm), high α (∼7.61), and high energy storage density (∼140.2 mJ/cm 3 ). The impedance spectra and electrical modulus results show that the dielectric properties of the prepared ceramics follow the internal barrier layer capacitor model. The enhanced tan δ and improved nonlinear properties of the doped samples are associated with the increased grain boundary resistance and Schottky barrier. These results provide important clues and valuable insights for realizing bifunctional ACTO materials with a giant ɛ ′, low tan δ , and excellent nonlinear properties.