Synthesis, phase segregation and properties of piezo-/ferroelectric (1-x)Pb(Sc1/2Nb1/2)O3-xPbTiO3 single crystals

Single crystals of the (1-x)Pb(Sc1/2Nb1/2)O-3-xPbTiO(3) [PSN-PT] solid solution are synthesized by the high-temperature solution method using PbO flux with B2O3 additive. The grown PSN PT single crystals contain a Ti concentration lower than the nominal composition (x = 0.425 - 0.51). The effective phase segregation coefficient is found to be k = 0.73 for the solid solution. Based on the segregation trend, the PSN-PT crystals of compositions within the morphotropic phase boundary (MPB) region are successfully grown. The MPB crystals show good dielectric and ferroelectric properties with a maximum dielectric constant of 60,000 (at 1 kHz) at T-C = 213 degrees C and a remnant polarization of 25 mu C/cm(2) at room temperature. The electromechanical coupling factor k(33) of the pre-poled crystals reaches 78%. The T-C and T-MPB the PSN-PT crystals are much higher than those of the Pb(Mg1/3Nb2/3)O-3 (PMN)-PT and Pb(Zn1/3Nb2/3)O-3 (PZN)-PT piezoerystals, making them very interesting high-T-C and high-performance piezoelectric materials. (c) 2005 Elsevier B.V. All rights reserved.