Effect of PMN modification on structure and electrical response of xPMN-(1-x)PZT ceramic systems

The structural and electrical properties of xPb(Mg1/3Nb2/3)O-3-(1-x)Pb(Zr,Ti)O-3 ternary ceramic system with the composition near to the morphotropic phase boundary(MPB) and of xPb(Mg1/3Nb2/3)O-3-(1 -x)Pb(Zr0.47Ti0.53)O-3 ceramics were investigated as a function of the Pb(Mg1/3Nb2/3)O-3 (PMN) content by scanning electron microscopy (SEM), X-ray diffraction (XRD), dielectric and piezoelectric spectroscopy and polarization-electric field measurement technique. Studies were performed on the samples prepared by a columbite precursor method for x = 0.125, 0.25 and 0.5. Room temperature SEM investigations revealed common trends in the grain structure with increasing PMN content. XRD analysis demonstrated that with increasing PMN content in xPb(Mg-1/3 Nb-2/3)O-3-(1-x)Pb(Zr0.47Ti0.53)O-3, the structural change occurred from the tetragonal to the pseudocubic phase at room temperature. Changes in the dielectric and ferroelectric behavior were then related to these structural trends and further correlated with the piezoelectric properties. The results of ferroelectric hysteresis measurements, in conjunction with dielectric spectroscopy, demonstrated an intermediate, relaxor-like behavior between normal and relaxor ferroelectrics in the solid solution system, depending on the PMN content. (C) 2002 Elsevier Science Ltd. All rights reserved.