Characteristic electrical properties of Pb(Sc_1/2Nb_1/2)O₃–PbTiO₃ ferroelectric crystals

Perovskite-type Pb(Sc_1/2Nb_1/2)O₃–PbTiO₃ single crystals have been obtained by the top-seeded solution growth technique. The structure type and phase purity were verified by X-ray diffraction analyses. Crystals with morphotropic phase boundary compositions can be grown from nominal material with PT content in the range of 0.50–0.53. The dielectric spectra of the as-grown crystals present normal ferroelectric behavior. The temperature of the maximum dielectric constant of PSN–PT crystals is determined to be 500.15–562.15 K. And the depolarization temperature is in the range of 478.15–415.15 K, which is higher than Pb(Mg_1/3Nb_2/3)O₃–PbTiO₃ and Pb(Zn_1/3Nb_2/3)O₃–PbTiO₃ crystals. At room temperature, the hysteresis loops of the (001)-oriented Pb(Sc_1/2Nb_1/2)O₃–PbTiO₃ crystals are well developed. The maximum remanent polarization is detected for x = 0.52, and it is 37 µC cm⁻² with the coercive field and being 5 kV cm⁻¹. The piezoelectric coefficients of Pb(Sc_1/2Nb_1/2)O₃–PbTiO₃ crystals at room temperature were obtained with the maximum value of 1420 pC N⁻¹ for the composition with PT content 0.515, which is the maximum among the reported results.