Nonlinear Property of (Nb₂O₅, SrCO₃, Ge, GeO₂)‐Codoped TiO₂‐Based Varistor Ceramics

Abstract

This study investigated the influence of codoping with Ge and GeO2 on the nonlinear coefficient α and the breakdown voltage EB of TiO2–Nb2O5–SrCO3 varistor ceramics. Ge–GeO2 codoping notably changed the microstructure of the TiO2–Nb2O5–SrCO3 ceramics, increased α, and decreased EB. When the doping contents of Nb2O5 and SrCO3 were 0.1 and 0.2 mol%, respectively, the optimum doping content of 0.25 mol% Ge and 0.75 mol% GeO2 exhibited high α (11.6), low EB (13.8 V/mm), and high grain‐boundary barrier ΦB (0.96 eV). These results are superior to previous findings. In addition, Ge and GeO2, which function as sintering aids, reduced the sintering temperature caused by the low melting point. The optimal sintering temperature was 1260°C for the TiO2–Nb2O5–SrCO3 ceramics doped with Ge and GeO2.

Varistor properties of TiO₂–Ta₂O₅–CaCO₃ ceramics doped with GeO₂

“…Parameters such as ¡, E B , and leakage current (J L ) were measured using a varistor direct-current instrument. The grain boundary barrier height () B ) of the samples was calculated using the following formula: 19…”

Doping Mechanism of Ge4+ Ions in Ge4+‐Doped TiO2

“…Wang et al synthesized Ge@ graphene@TiO 2 nanofibers as high‐capacity and cycle‐stable anode for lithium and sodium ion battery. Kang et al investigated the nonlinear properties of Ge and GeO 2 co‐doped TiO 2 . Long et al found Ge‐doped TiO 2 can be active for overall water splitting.…”