Polaron conductivity mechanism in 0.5Pb(Zr_(0.575)Ti _(0.425))O_30.5Pb(Fe_(2/3)W_(1/3))O _3

摘要

0.5Pb(Zr_(0.575)Ti_(0.425))O_30.5Pb(Fe _(2/3)W_(1/3))O_3 (0.5PZT0.5PFW) belongs to the solid solutions which exhibits some bi-relaxor properties, with both ferroelectric and magnetic relaxor properties. Recently it was reported that the thin film of 0.8Pb(Zr_(0.53)Ti_(0.47))O_30.2Pb(Fe _(2/3)W_(1/3))O_3 (0.8PZT0.2PFW) has a new and very large magnetoelectric effectswitching from P_r to zero with applied magnetic field of less than a Tesla. We report dielectric and ac electric conductivity investigations of the 0.5PZT0.5PFW bulk ceramics. A detailed analysis of the temperature dependence of the universal dielectric response parameter s in terms of the theoretical model for tunneling of small polarons revealed that below 450 K this mechanism governs the charge transport in the system. This provides a new understanding of the magnetoelectric effect in 0.5PZT0.5PFW.