Dielectric and energy storage properties of BZN ceramics fabricated by roll-forming

A linear dielectric is characterized by a linear relationship between polarization and electric field. Bi-based pyrochlore (Bi₁.₅Zn₀.₅)(Zn₀.₅Nb₁.₅)O₇ ceramics have been extensively studied due to their ultra-low dielectric loss, moderate dielectric constant, and relatively low sintered temperature. However, most studies have been conducted on samples prepared by cold isostatic pressing, a method that results in ceramic samples with lower density compared to those fabricated via roll-forming. Therefore, this study employed the roll-forming method to fabricate BZN ceramic thick films (∼100 μm) and investigated their dielectric temperature stability and energy storage properties at various sintered temperatures. The study results demonstrate that BZN ceramics can be sintered below 1000 °C without the need for sintering aids (e.g., glass). Moreover, the BZN sample sintered at 980 °C exhibits a high dielectric constant (∼156), an extremely low dielectric loss (<0.0002), and excellent energy storage properties. It maintains linear behavior even under an electric field of 450 kV/cm, with η > 98.5 % and W_rec = 1.7068 J/cm³. Furthermore, the pulse charge-discharge performance of the BZN-980 ceramic sample was also investigated. These results establish a solid foundation for the application of BZN ceramics and provide valuable insights for subsequent research.