Dresden 2020 – wissenschaftliches Programm
Die DPG-Frühjahrstagung in Dresden musste abgesagt werden! Lesen Sie mehr ...
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
KFM: Fachverband Kristalline Festkörper und deren Mikrostruktur
KFM 9: Focus: Polar oxide crystals and solid solutions
KFM 9.6: Vortrag
Mittwoch, 18. März 2020, 11:20–11:40, TOE 317
Electrical and electromechanical properties of single crystalline Li(Nb,Ta)O3 solid solutions at elevated temperatures — •Yuriy Suhak1, Bujar Jerliu1, Dmitry Roshchupkin2, Boris Red'kin2, Steffen Ganschow3, Günter Borchardt1, Klaus-Dieter Becker4, and Holger Fritze1 — 1Clausthal University of Technology, Goslar, Germany — 2Institute of Microelectronics Technology and High Purity Materials, Chernogolovka, Russia — 3Leibniz Institute for Crystal Growth, Berlin, Germany — 4Braunschweig University of Technology, Braunschweig, Germany
Piezoelectric materials with high piezoelectric coefficients that can be operated above 500 °C are in high demand for industrial actuating applications. Lithium niobate (LiNbO3) and lithium tantalate (LiTaO3) possess high piezoelectric coefficients, however their usage is limited by thermal instability (LiNbO3) and low Curie temperature (LiTaO3). This work focuses on the electrical and electromechanical properties of Li(Nb,Ta)O3 crystals that are expected to overcome the mentioned restrictions of individual compounds. The electrical and electromechanical properties are investigated by means of impedance spectroscopy and resonant ultrasound spectroscopy, respectively. The experiments are performed in a gas-tight tube furnace, which allows working temperatures up to 1000 °C. The investigations revealed, that Li(Nb,Ta)O3 solid solutions show lower conductivity than LiNbO3 at high temperatures and low oxygen partial pressures (pO2). At 930 °C and pO2 of 10-15 bar the conductivity of LiNb0.29Ta0.71O3 sample is almost two orders of magnitude lower than that of LiNbO3.