Dielectric and piezoelectric properties for 0.62Pb(Mg1/3Nb2/3)O3-0.38PbTiO3 single crystals

The dielectric and piezoelectric properties of 0.62Pb(Mg1/3Nb2/3)O-3-0.38PbTiO(3) single crystal (PMNT62/38) were investigated in this work. Power X-ray diffraction demonstrated PMNT62/38 had a tetragonal structure at room temperature. The Curie temperature was 187 degreesC on heating. The poled and as-grown dielectric constants E-c of [001] oriented PMNT62/38 at room temperature were similar to500 and similar to5000, respectively. The remanent polarization P-r and coercive field E-c for [001] oriented one were 34.2 muC/cm(2) and 8.25 kV/cm, respectively. The strain at 15 kV/cm and -15k V/cm were 0.078 and 0.125%, respectively. The piezoelectric constant d(33) was similar to350 pC/N. The electromechanical coupling coefficients; 0.89 of k(33), 0.61 of k(t), 0.46 of k(31) and 0.45 of k(15) were calculated from measured resonance and anti-resonance frequencies by impedance resonance techniques. In single domain process it was found the re-oriented domains of [001] poled PMNT62/38 were instable, which caused it hard to align the spontaneous polarizations to create a single domain crystal. (C) 2002 Elsevier Science Ltd and Techna S.r.l. All rights reserved.