Synthesis and characterizations of the (1-x)Pb(Sc1/2Nb1/2)O3-xPbTiO3 solid solution ceramics

We report a systematic study of the (1-x)Pb (Sc1/2Nb1/2)O-3-xPbTiO(3) (PSN-PT) solid solution in the form of ceramics with compositions at or near the morphotropic phase boundary (MPB) region (0.35 <= x <= 0.50). The PSN-PT ceramics have been synthesized by an improved two-step wolframite precursor method. The synthetic process has been optimized in terns of calcining and sintering conditions. Both dielectric permittivity measurements and differential scanning calorimetry (DSC) show a clear peak at T-C, at which the transition from the paraelectric to ferroelectric phase takes place. Interestingly, the solid solution of the MPB compositions displays a T-C>200 degrees C, i.e. higher than the T-C of the Pb(Mg1/3Nb2/3)O-3-PbTiO3 and Pb(Zn-1/3 Nb-2/3)O-3-PbTiO3 solid solutions, making the PSN-PT system very promising piezoelectric and ferroelectric materials for high-temperature applications. A dielectric maximum as high as 50,000 is obtained for the 0.65PSN-0.35PT ceramic with losses smaller than 0.05. The values of the remnant polarization and the strain level of the PSN-PT ceramics are comparable to those of the PZT ceramics.