Bridgman Growth and Photoelectronic Property of Relaxor-Based Ferroelectric Single Crystal Pb(Sm1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3

A relaxor-based ferroelectric single crystal with the nominal composition of xPb(Sm0.5Nb0.5)O3-(0.7‒x) Pb(Mg1/3Nb1/3)O3-0.3PbTiO3 (x = 0.01, 0.02, and 0.03) was grown by the vertical Bridgman process. The electrical properties and the ferroelectric domains, as well as the luminescent characteristics of the single crystals, were investigated systematically. The piezoelectric coefficient d33 of the single crystals are slightly higher than that of the undoped PMN-PT single crystal under direct current polarization, while the crystal wafers gain a much higher d33 value upon being polarized with alternating current voltage. The single crystals possess a decreased phase transition temperature of around 60 °C and a decreased Curie temperature of 92~116 °C compared with the undoped PMN-PT single crystal. The crystal wafers polarized with alternating current voltage exhibited a desirable optical transmittance, which is associated with the domain structure changes inside the crystal medium. The domain density of the crystal wafers under alternating current polarization was significantly decreased compared with the direct current polarized crystal wafers. The luminescent spectra of the crystal wafers exhibit the typical emission peaks corresponding to the characteristic transition of Sm3+ ions in the crystal lattice.