Dresden 2009 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
DF: Fachverband Dielektrische Festkörper
DF 12: Poster II
DF 12.2: Poster
Mittwoch, 25. März 2009, 09:30–12:30, P5
Anomalous strain hysteresis of poled Nd–Mn-doped PZT fibres — •Christoph Pientschke1, Ralf Steinhausen1, Horst Beige1, Reinhard Krüger2, Tobias Müller2, Uta Helbig2, Dieter Sporn2, Carsten Schuh3, Stefan Denneler3, and Hugo Schlich4 — 1Martin-Luther-University Halle, Physics Department, PFM, 06099 Halle — 2Fraunhofer ISC, Würzburg — 3Siemens AG, CT MM 2, Munich — 4MaTeck GmbH, Jülich
PZT fibres were produced using the sol–gel process. The PZT was doped with 2 mol% neodymium and 1.1 or 0.75 mol% manganese. After sintering at 900 ∘C the fibres were fine grained (grain size ≈ 1µm). The fibres were embedded in a polymer for characterisation. The resulting 1–3-composites were poled with a DC voltage for 11/2 hours. By applying a bipolar sinusoidal voltage with high amplitude (7 kV/mm) and a frequency of 10 Hz the strain and polarisation were measured. The resulting strain-loops are strongly asymmetric. For the half period with applied fields parallel to the poling field the strain loop exhibits a rather linear shape. For the half period in reversed direction the loop inflates and closes with hardly no strain change. The asymmetry of strain-loops is more pronounced for smaller grains. For samples with 1.1 mol% Mn strain switching seems to be suppressed between room temperature up to 80 ∘C. The asymmetry of the strain loops is switchable by a subsequent poling process. The blocking of strain switching was proved by measurements of the piezoelectric coefficient d33 with superimposed electric field. For 0.75 mol% Mn-content strain switching occurs. All these properties are believed to be a feature of the ceramics.