Superior Reliability Via Two‐Step Sintering: Barium Titanate Ceramics

作者：Qiancheng Zhao, Huiling Gong, Xiaohui Wang, I‐Wei Chen, Longtu Li · 发表于：Journal of the American Ceramic Society · 年份：2015 · DOI：10.1111/jace.13940 · 被引用次数：44 · 研究领域：Ferroelectric and Piezoelectric Materials、Microwave Dielectric Ceramics Synthesis、Advanced ceramic materials synthesis

Two‐step sintering ( TSS ) in a reducing atmosphere has been employed to obtain fine‐grain BaTiO 3 ceramics with a core‐shell microstructure, a more uniform grain‐size distribution, and superior reliability for multilayer ceramic capacitor applications. Compared to ceramics of the same composition conventionally sintered for about the same time, TSS ceramics feature a thinner shell thickness thus a stronger dopant localization, which leads to a lower concentration, higher internal resistance and more dopant‐ association. Improved reliability is manifest in a 50% higher breakdown strength at ambient temperature and a 400% longer endurance time to withstand DC stress at 185°C, in addition to a less field‐and‐temperature‐dependent capacitance. A scaling analysis of the redistribution and endurance dynamics identifies transmission across the shell‐grain‐boundary region as the critical element beneficially impacted by core‐shell structure and two‐step sintering.