Electromechanical and electro-optic properties of xBiScO(3)-yBiGaO(3)-(1-x-y)PbTiO3 single crystals

Single crystals in the xBiScO(3)-yBiGaO(3)-(1-x-y)PbTiO3 (BS-BG-PT) system were grown by the high temperature solution method using Pb3O4 and Bi2O3 as the flux. The dielectric permittivity (e,) at room temperature for unpoled tetragonal crystals was determined to be 500-600 with dielectric loss tangents less than 0.3%. The Curie temperature was found to be around similar to420-450degreesC, with a dielectric maximum, exhibiting relaxor behavior. The longitudinal piezoelectric coefficient (d(33)) was found to be similar to300pC/N for [001] oriented tetragonal crystals with electromechanical coupling factor (k(33)) of 75%, with a shear mode, d(15)similar to290pC/N and k(15)similar to45%, lateral mode, d31 similar to -55 pC/N and k31 similar to -37%. The remnant polarization (P-r) was 46 muC/cm(2) with a coercive field (E-c) of 43 kV/cm at 1 Hz and DC field of 60 kV/cm. The linear electro-optic (E-O) coefficients of poled crystals determined using an automated scanning Mach-Zehnder interferometer method at room temperature and wavelength of 632.8nm were r(33) = 36 and r(13) = 4 pm/V, respectively. (C) 2002 Elsevier Science B.V. All rights reserved.