Effects of CaZrO3 on X8R Nonreducible BaTiO3-BasedDielectric Ceramics

• Published in: Journal of the American Ceramic Society Vol. 94; no. 11; pp. 3856 - 3862
• Main Authors: Yao, Guofeng, Wang, Xiaohui, Sun, Tieyu, Li, Longtu
• Format: Journal Article
• Language: English
• Published: Malden, USA Blackwell Publishing Inc 01.11.2011
• Subjects: Capacitance; Ceramics; Core-shell structure; Direct current; Doping; Enrichment; Grain boundaries; Insulation
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/j.1551-2916.2011.04563.x

Effects of CaZrO3 on BaTiO3–MgO–MnO2–Y2O3 nonreducible ceramics were investigated. The specimens modified by CaZrO3 in the range from 0 to2 mol% were prepared via conventional mixing method. Transmission electron microscopic analysis revealed that doping elements were enriched at grain boundaries and “core–shell” structures were formed. The addition of CaZrO3 could lower the sintering temperature. The Curie temperature was shifted to a higher point with increasing CaZrO3, attributed to the existence of an internal stress produced by lattice mismatch between grain cores and shells. Temperature dependence of dielectric constant and capacitance change were also dependent on CaZrO3 content. With the increasing of CaZrO3 content, the insulation resistivity was improved whereas the degradation under direct current electrical field was significant. Therefore, a proper CaZrO3 content is crucial to obtain high performance X8R nonreducible BaTiO3‐based dielectrics.