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

• Published in: Ceramics international Vol. 29; no. 2; pp. 145 - 150
• Main Authors: Cao, H, Fang, B, Luo, H, Sun, Y, Guo, J
• Format: Journal Article
• Language: English
• Published: 01.01.2003
• ISSN: 0272-8842
• DOI: 10.1016/S0272-8842(02)00098-6

The dielectric and piezoelectric properties of 0.62Pb(Mg1/3Nb2/3)O3-0.38PbTiO3 single crystal (PMNT62/38) were studied. XRD showed that PMNT62/38 had a tetragonal structure at room temperature. The Curie temperature was 187 C on heating. The poled and as-grown dielectric constants of [001] oriented PMNT62/38 at room temperature were about 500 and about 5000, respectively. The remanent polarisation and coercive field were 34.2 microCoulomb/cm2 and 8.25 kV/cm, respectively. The strain at 15 kV/cm and -15 kV/cm were 0.078 and 0.125%, respectively. The piezoelectric constant d(33) was about 350 pC/N. The electromechanical coupling coefficients (k33 of 0.89; kt of 0.61; k31 of 0.46; k15 of 0.45) were calculated from measured resonance and anti-resonance frequencies by impedance techniques. In the single domain process, the re-oriented domains of [001] poled PMNT62/38 were found to be unstable, which made it difficult to align the spontaneous polarisations to create a single domain crystal. 11 refs.