Evidence of macro–micro domain transition in poled PMN–PZT ceramics

The dielectric properties of unpoled and poled Pb0.88Ba0.06Sr0.06(Mg1/3Nb2/3)0.37Zr0.375Ti0.255O3 (modified PMN–PZT) ceramics were investigated. It was found that the dielectric constant increased while the loss tangent decreased after poling. A frequency independent abrupt transition in the dielectric constant and loss tangent responses was observed for the poled ceramics. This abnormal behavior was believed to be correlated with the macro–micro domain transition and the corresponding pyroelectric measurement exhibited a narrow peak at the normal-relaxor transition temperature Tnr. Furthermore, the presence of double-loop-like hysteresis and two types of current peaks at a temperature slightly higher than Tnr showed another strong evidence of this transition.