Journal of the European Ceramic Society, Volume 34, Issue 7, July 2014, Pages 1727–1732.
Aurang Zeb, Steven J. Milne.
Institute for Materials Research, University of Leeds, Leeds LS2 9JT, United Kingdom.
Abstract
The dielectric and ferroelectric properties of the ceramic system, (1 − x)Ba0.8Ca0.2TiO3–xBi(Zn0.5Ti0.5)O3, were investigated for compositions 0 ≤ x ≤ 0.4. X-ray powder diffraction patterns indicated tetragonal symmetry at x ≤ 0.05, switching to pseudocubic at x ≥ 0.1, with a single-phase solid solution limit at 0.2 < x < 0.3. The x = 0 and 0.05 samples were ferroelectric; a change to relaxor behaviour occurred atx ≥ 0.1, with broad frequency dependent peaks in plots of relative permittivity versus temperature. A significant reduction in the temperature dependence of relative permittivity occurred at x = 0.3, with ɛr = 1030 ± 15% over the temperature range ∼25–425 °C, and loss tangent, tan {Delta} ≤ 0.01 from 110 °C to 420 °C. The dc resistivity values for x = 0.3 were ∼109 Ω m at 300 °C and ∼106 Ω m at 450 °C.