Structural quality of relaxor-based ferroelectric 〈1 1 1〉 oriented Pb(Mg1/3Nb2/3)O3–0.26PbTiO3 single crystals

0.74Pb(Mg1/3Nb2/3)O3–0.26PbTiO3 (PMN–0.26PT) single crystals have been grown by a modified Bridgman technique. X-ray rocking curves, domain structures, and dielectric properties have been investigated on 〈1 1 1〉 oriented as-grown, annealed, and poled PMN–0.26PT single crystals at various parts in the same boule. The results reveal that the structural quality of as-grown PMN–PT single crystals can be significantly improved by appropriate thermal annealing and poling. At room temperature, 〈1 1 1〉 oriented poled PMN–0.26PT single crystals have rocking curve full width at half maximum FWHM < 2 arc min and dielectric loss tan δ < 0.2%.