Enhanced dielectric reliability in the X9R‐type Bi1/2Na1/2TiO3‐CaZrO3 relaxor ferroelectric ceramics

• Published in: Journal of the American Ceramic Society 2024-06, Vol.107 (6), p.4252-4262
• Main Authors: Lee, Ju‐Hyeon, Yeo, Tae‐Soo, Jo, Wook
• Format: Article
• Language: English
• Subjects: Barium titanates; bismuth sodium titanate; Calcium zirconate; Ceramics; Composition; Curie temperature; Dielectric breakdown; Dielectric loss; dielectric materials/properties; Dielectric strength; Ferroelectricity; ferroelectricity/ferroelectric materials; multilayer capacitor; Operating temperature; relaxors; Reliability; Room temperature; Structural analysis; Thermal stability
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.19783

High‐performance dielectric ceramic capacitors for automotive applications require high operation temperature, thermal stability, and reliability for dielectric ceramics. A broad composition search has been carried out to replace the existing BaTiO3‐based dielectrics having limited upper operating temperature due to the relatively low Curie temperature at around 120°C. However, most of the developed compositions are too complicated and compositionally sensitive, making them difficult to commercialize. This study introduces a dielectrically reliable ceramic system based on Bi1/2Na1/2TiO3 (BNT) with a wide operation temperature range simply by adding paraelectric CaZrO3 (CZ). At 15 mol% addition of CZ to BNT, the permittivity variation within ±15% from −55 to 280°C was achieved, which surpasses the EIA‐X9R standard. Moreover, the dielectric reliability was shown with low dielectric loss (tanδ