Growth and characterization of ternary BiScO3-Pb(Cd1/3Nb2/3)O-3-PbTiO3 ferroelectric single crystals with high Curie temperature

Ferroelectric single crystals of a ternary perovskite solid solution, BiScO3-Pb(Cd1/3Nb2/3)O-3-PbTiO3(BS-PCN-PT), have been successfully grown by the top-seeded solution growth method for the first time. The crystals with dimensions up to 2.5 x 2.5 x 1 cm(3)were obtained. The structure of the BS-PCN-PT crystals has been studied by high-resolution X-ray diffraction, combined with polarized light microscopy, showing a tetragonal symmetry. The grown crystals exhibit a pseudo-cubic morphology with the (001) facets, suggesting a dominant {100}-growth process. Interestingly, a single ferroelastic domain state was found in most (001) platelets cut from the as-grown crystals. The domain structures and characteristics were carefully investigated by a combination of polarized light microscopy and piezoresponse force microscopy. The single-domain crystals possess a high average coercive field (E-c similar to 30 kV cm(-1)) and a high remanent polarization (25 mu C cm(-2)). An unpoled piezoelectric constantd(33)of the single-domain crystal is up to 111 pC N(-1)due to its self-polarization. The Curie temperatureT(C)is found to be 423 degrees C by means of dielectric measurements, which is much higher than that of relaxor-based Pb(Mg1/3Nb2/3)O-3-PbTiO3(PMN-PT) piezocrystals. Moreover, the dielectric properties exhibit an excellent thermal stability up to 300 degrees C. A careful discussion about how the domain state may affect electromechanical properties has been carried out. The highT(C), large coercive electric field, and high remanent polarization of the single-domain BS-PCN-PT crystals make this material a promising candidate for applications in a wider temperature range and at higher power compared to the PMN-PT crystals.