Diffuse phase transition and high electric field properties of BaCe y Ti 1- y O 3 relaxor ferroelectric ceramics

Pure perovskite BaCeyTi1-yO3 ceramics with compositions y=0.10, 0.20 and 0.30 have been prepared by solid state reaction. The temperature and frequency dependence of dielectric properties (permittivity, dielectric loss and dielectric modulus) of the ceramics has been investigated. A diffuse phase transition is typical for all the compositions, with a reduction of the Curie temperature with increasing Ce addition. If in the case of the sample with 0.10 Ce content, no frequency shift of the phase transition temperature (Tm) is noticed, a relaxor-like ferroelectric character become predominant for concentrations 0.20 and 0.30. The ceramic with y=0.20 presents higher tunability, a reduced hysteretic behavior and reasonable low dielectric losses at room temperature, which makes this composition a very good candidate for tunable capacitors applications.