In-situ-Aufklärung der strukturellen Nah- und Fernordnung sowie gezielte nasschemische Phasensysteme perowskitverwandter Schichtsysteme
Zusammenfassung der Projektergebnisse
Reversible structural changes of the near-surface regions of the STO wafer at RT caused by a static-electric-field-induced redistribution of oxygen vacancies have been found. The phenomenon is of interest for application for adaptive X-ray optics. Application of the d.c. electric field (E > 4 kV/cm) to the single-crystalline wafer of PMN-PT demonstrating dominant converse piezoelectric effect lead to a reversible phase transition in a skin region near the sample surface, which results in an increasing of the piezoelectric properties of the wafer. The strained state of the 30 nm...100 nm STO/30 nm La0.7Sr0.3MnO3 (LSMO) films deposited on PMN-PT substrate can be effectively controlled by the inverse piezoelectric effect of the substrate under application of the static electric field at RT. The structural changes in the materials are highlighted by means of wide-angle X-ray diffraction and X-ray absorption spectroscopy.
