Controlling the grain growth and grain boundary morphology is of great importance in the manipulation of electrical properties of electro-ceramics. However, it has been a challenge to achieve dense varistor ceramics with grain sizes in submicrons and nanometers using conventional thermal sintering at high temperatures. Here we present a strategy to fabricate dense ZnO based ceramics with controlled grain growth and thin grain boundaries using cold sintering process (CSP). With CSP, the sintering temperature of ZnO based ceramics dramatically drops from 1100 °C to 300 °C. The Bi₂O₃, Mn₂O₃, and CoO dopants suppress the grain growth of ZnO under CSP conditions, and Bi-rich intergranular films (2−5 nm) can be observed along grain boundaries. The cold sintered ZnO-Bi₂O₃-Mn₂O₃-CoO ceramic shows a non-linear coefficient of 33.5, and a superior breakdown electric field of 3550 V/mm. This work thus demonstrates that CSP is a promising technique for designing new submicron-/nano-ceramics with superior performances.

控制晶粒的生长和晶界的形态对电子陶瓷电性能的控制非常重要。然而，使用高温下的常规热烧结来获得具有亚微米和纳米粒度的致密压敏电阻陶瓷是一个挑战。在这里，我们提出一种使用冷烧结工艺（CSP）制造具有受控晶粒生长和细晶界的致密ZnO基陶瓷的策略。使用CSP，基于ZnO的陶瓷的烧结温度从1100°C急剧下降至300°C。Bi ₂ O ₃，Mn ₂ O ₃，并且CoO掺杂剂抑制了CSP条件下ZnO的晶粒长大，并且沿晶界可以观察到富含Bi的晶间膜（2-5 nm）。冷烧结的ZnO-Bi ₂ O ₃ -Mn ₂ O ₃ -CoO陶瓷的非线性系数为33.5，优良的击穿电场为3550 V / mm。因此，这项工作表明CSP是一种设计性能优异的新型亚微米/纳米陶瓷的有前途的技术。