Berlin 2008 – wissenschaftliches Programm
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DF: Fachverband Dielektrische Festkörper
DF 2: Electric, electromechanical and optical properties I
DF 2.4: Vortrag
Montag, 25. Februar 2008, 11:20–11:40, EB 107
Time- and frequency-domain polarization imaging on poly(vinylidenefluoride-co-trifluoroethylene) films — •Rosaura Flores Suárez1, Axel Mellinger1, Werner Wirges1, Reimund Gerhard1, Cong-Duc Pham2, Anca Petre2, Laurent Berquez2, and Didier Marty-Dessus2 — 1University of Potsdam, Department of Physics, 14469 Potsdam, Germany — 2Paul Sabatier University, Laboratory on Plasma and Conversion of Energy, 31062 Toulouse, France
Three-dimensional tomography of space-charge and polarization distributions are of high interest for the electrical characterization of new dielectric materials. In this work, two non-destructive thermal methods called TPT (Thermal-Pulse Tomography) and FLIMM (Focused Laser-Intensity Modulation Method) are presented and compared. FLIMM is implemented in the frequency domain, while TPT works in the time domain. In an effort to further increase the lateral resolution while minimizing the thermal stress on the sample, 3D polarization images of poly(vinylidenefluoride-co-trifluoroethylene) (PVDF-TrFE) films poled with a well-defined grid-pattern electrode were obtained. The PVDF-TrFE (65%-35%) films (12 µm thickness) were prepared by means of drop casting. The 3D polarization maps show a polarization starting at a depth of 0.2 µm. In low- and high-resolution scans, the details of the grid electrode are very well reproduced and non-uniformities of polarization along some arms are seen, respectively. These results will be compared with simulations taking into account the 3D heat flow.