Growth and characterization of high-Curie temperature Pb(Lu1/2Nb1/2)O3-Pb(Mg1/3Nb2/3)O3-PbTiO3 ternary single crystal by modified Bridgman technique

A new relaxor-based ferroelectric ternary system Pb(Lu1/2Nb1/2)O-3-Pb(Mg1/3Nb1/2)O-3-PbTiO3 (PLN-PMN-PT), with a combination of a high-Curie temperature system Pb(Lu1/2Nb1/2)O-3-PbTiO3 (PLN-PT) and a high piezoelectricity system Pb(Mg1/3Nb2/3)O-3-PbTiO3 (PMN-PT), was investigated in this paper. Single crystal PLN-PMN-PT with dimensions of Phi 20 x 45 mm(3) was grown successfully by the modified Bridgman technique for the first time. The studies of structure and composition of the as-grown crystal showed structural consistency but compositional deviation along the growth direction. The < 001 >-oriented wafers of the PLN-PMN-PT single crystal showed excellent electrical properties at room temperature: epsilon(33)similar to 4500, tan delta similar to-0.5%, d(33)similar to 2300 pC/N. The crystal was found to exhibit high Curie temperature (Tc similar to 176 degrees C), rhombohedral-tetragonal phase transition temperature (T-RT similar to 108 degrees C) and coercive field (E-C similar to 8.1 kV/cm), superior to those of PMN-0.3PT single crystal. Studies of temperature dependence ferroelectric properties showed that high values of k(33) and d(33) could be maintained up to the T-RT. These results showed that PLN-PMN-PT piezoelectric single crystal has a higher Curie temperature and coercive tick! with excellent electrical properties, making the crystal a promising candidate for high-power transducer applications in a broad temperature range. (C) 2015 Elsevier B.V. All rights reserved.