Dielectric properties and high tunability of Ba(Ti0.7Zr0.3)O3 ceramics under dc electric field

The effect of dc electric field (E) on the dielectric properties of Ba(Ti0.7Zr0.3)O3 ceramics with an obvious ferroelectric-relaxor behavior (Tm∼229 K, 10 kHz) is reported. The dielectric constant is greatly suppressed and a low loss is obtained under dc electric fields (⩽40 kV/cm). The low loss (tan δ∼0.002) and high tunability (∼45%) were obtained for the Ba(Ti0.7Zr0.3)O3 ceramics around 300 K, indicating that it is a promising candidate for tunable materials at room temperature. The field dependence of the temperature (Tm) of the dielectric constant maximum follows the ΔTm∼E2/3 relation, indicating a second-order phase-transition-like behavior.