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Superior Reliability Via Two‐Step Sintering: Barium Titanate Ceramics
Author(s) -
Zhao Qiancheng,
Gong Huiling,
Wang Xiaohui,
Chen IWei,
Li Longtu
Publication year - 2016
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/jace.13940
Subject(s) - materials science , sintering , barium titanate , ceramic capacitor , ceramic , microstructure , composite material , grain boundary , grain size , dopant , metallurgy , capacitor , optoelectronics , doping , electrical engineering , voltage , engineering
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 V O ∙ ∙concentration, higher internal resistance and more dopant‐ V O ∙ ∙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 V O ∙ ∙redistribution and endurance dynamics identifies V O ∙ ∙transmission across the shell‐grain‐boundary region as the critical element beneficially impacted by core‐shell structure and two‐step sintering.