Influence of dc bias field on dielectric properties of high-k Y5V (Ba, La)(Ti, Ce)O3 ceramic

The influence of dc bias field (E-bias) on the dielectric properties of high-k Y5V (Ba0.94La0.03)(Ti0.94Ce0.05)O-3 ceramic (BL3TC5) was investigated. With increasing E-bias from 1 to 12.5 kV/cm, dielectric permittivity and dielectric loss were suppressed, and the permittivity maximum decreased linearly. Upon field heating and field cooling, the temperature of the permittivity maximum shifted to higher temperatures; however, the dielectric heat relaxation decreased with increasing E-bias. As E-bias >= 10 kV/cm, the frequency dispersion vanishes. The model of polar nano-domains is proposed to account for dielectric behavior under dc bias field. In addition, BL3TC5 shows high turability (similar to 67%) and low loss (<0.008) at room temperature. (C) 2009 Elsevier B.V. All rights reserved.