Stability of High-Temperature Dielectric Properties for (1 − x)Ba0.8Ca0.2TiO3-xBi(Mg0.5Ti0.5)O3 Ceramics

• Published in: Journal of the American Ceramic Society Vol. 96; no. 9; pp. 2887 - 2892
• Main Authors: Zeb, Aurang, Milne, Steven J.
• Format: Journal Article
• Language: English
• Published: Blackwell Publishing Ltd 01.09.2013
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/jace.12412

Ceramics in the solid solution system, (1 − x)Ba0.8Ca0.2TiO3–xBi(Mg0.5Ti0.5)O3, were prepared by a conventional mixed oxide route. Single‐phase perovskite‐type X‐ray diffraction patterns were observed for compositions x < 0.6. A change from tetragonal to single‐phase cubic X‐ray patterns occurred at x ≥ 0.1. Dielectric measurements indicated relaxor behavior for x ≥ 0.1. Increasing the Bi(Mg0.5Ti0.5)O3 content improved the temperature sensitivity of relative permittivity ϵr at high temperatures. At x = 0.5, a near‐plateau relative permittivity, 835 ± 40, extended across the temperature range, 65°C–550°C; the permittivity increased at x = 0.6 to 2170 ± 100 for temperatures 160°C–400°C (1 kHz). The corresponding loss tangent, tanδ, was ≤0.025 for temperatures between 100°C and 430°C for composition x = 0.5; at x = 0.6, losses increased sharply at >300°C. Comparisons of dielectric properties with other materials proposed for high‐temperature capacitor applications suggest that (1 − x)Ba0.8Ca0.2TiO3–xBi(Mg0.5Ti0.5)O3 ceramics are a promising base material for further development.