Ferroelectric relaxor behavior and dielectric properties of La/Y co-doped (Ba0.9Ca0.1)(Zr0.2Ti0.8)O3 ceramics

The ferroelectric relaxor behavior and dielectric properties of La2O3 and Y2O3 co-doped (Ba0.9Ca0.1)(Zr0.2Ti0.8)O3 ceramics prepared by solid route were investigated. The phase structure, microstructures and dielectric properties of the as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy and impedance analyzer respectively. The results show that La3+ ions and Y3+ ions substitute for A-sites ions and B-sites ions respectively to enter the unit cell maintaining the perovskite structure of solid solution, inducing inhomogeneous microstructure, smaller grain size and lower density, then resulting the occurrence of ferroelectric relaxor behavior. The relaxor behavior was observed in (Ba0.9Ca0.1)0.995La0.005(Zr0.2Ti0.8)O3–x mol% Y ceramics and the degree of ferroelectric relaxation behavior is enhanced with the increase of Y3+ ions concentration. The dielectric constant increases with x = 0.0–0.1 then decreases with further addition, the sample with x = 0.1 shows a giant permittivity (21,736) with lower dielectric loss (0.063) and could be an attractive material for ceramic capacitor applications.