Effect of Ho‐Dy co‐doping on the electrical properties and reliability of BaTiO 3 ‐based nanoceramics for Base Metal Electrode Multilayer Ceramic Capacitor

Fine‐grained BaTiO 3 ‐based ceramics with an average grain size of 120−140 nm were prepared by a chemical coating method. The effect of Ho‐Dy concentration on the microstructure, dielectric properties, and reliability of BaTiO 3 ‐based nanoceramics was investigated. Results showed that appropriate doping contents of Ho and Dy provide the highest dielectric constant of 2323 at room temperature and the temperature stability satisfied EIA X7R specification. Higher doping concentration specimens exhibit lower dielectric constant but gentler temperature stability, indicating thicker grain shells. The failure time under the highly accelerated lifetime test increased along with the increase of Ho‐Dy and was consistent with the impedance analysis results. Doping elements are mainly distributed in grain shells, leading to an increase of resistance and activation energy. The compositions for the highest dielectric constant and best reliability were not the same, providing support for the composition design of dielectric layer material for different BME‐MLCC applications.