Variations in properties with composition in lead zirconate-titanate ceramics

Abstract

Lead zirconate-lead titanate ceramics, covering the compositional range 40 to 70 mole per cent lead zirconate, were prepared by cold pressing and sintering from co-precipitated powders. For these ceramics the maxima in the values of dielectric constant and electromechanical coupling factor that occur at the rhombohedral-tetragonal boundary were found to be higher and sharper than previously reported for . unmodified lead zirconate-titanate. Dielectric and mechanical losses were lower in the tetragonal than in the rhombohedral phase. Determination of the variations in properties with temperature confirmed the previously reported shift in the phase boundary toward higher zirconate compositions with increasing temperature. It was found that changes in electromechanical properties resulting from loss of lead oxide could be explained on the basis of the formation of a more titanaterich solid solution, accompanied by the precipitation of zirconia

Investigation of La-doped 0.25Pb(Zn1/3Nb2/3)O3-0.75Pb(ZrxTi1-x)O3 ceramics near morphotropic phase boundary

“…8 The P-E curve and S 33 -E curve of specimen with Zr/Ti053/47 reduces the dielectric losses. This result agrees with many reports [8,16,18,19] and was explained as polarization causes domain reorientation along one direction. And as observed in some researches [18,19], the dielectric losses show an increase tendency with the increase of the Zr/Ti ratio.…”

“…This result agrees with many reports [8,16,18,19] and was explained as polarization causes domain reorientation along one direction. And as observed in some researches [18,19], the dielectric losses show an increase tendency with the increase of the Zr/Ti ratio. Weston et al [19] considered that the tetragonal phase has lower dielectric loss than the rhombohedral phase because of a decrease in the mobility of the domain walls.…”

“…And as observed in some researches [18,19], the dielectric losses show an increase tendency with the increase of the Zr/Ti ratio. Weston et al [19] considered that the tetragonal phase has lower dielectric loss than the rhombohedral phase because of a decrease in the mobility of the domain walls. It is noteworthy that the dielectric losses of 0.25PZN-0.75PLZT ceramics are relative low compared with 0.3PZN-0.7PLZT ceramics reported [8,10,20].…”

The influence of sintering conditions on the dielectric and piezoelectric properties of PbZrTiO–PbMgNbO ceramic tubes

“…Combined with the above XRD results, it can be explained in terms of the phase transformation that takes from rhombohedral to tetragonal phase with the increase of sintering temperature. Generally, the tetragonal phase has higher coercive field than rhombohedral phase in the PZT-based ceramics [18]. As the volume fraction of tetragonal phase increases so does the coercive field.…”

Property improvement of 0.3Pb(Zn1/3Nb2/3)O3-0.7Pb0.96La0.04(ZrxTi1−x)0.99O3 ceramics by hot-pressing

“…Commonly, the maxima of dielectric coefficient and electromechanical coupling factor appear on the tetragonal side near the MPB. 25,26 The observed shifts of the maxima of d 33 and k p may be attributed to the shift of the MPB and the densification. This reasoning is supported by the XRD data.…”