Berlin 2001 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 19: Poster: New Methods, Thin Polymer Films, Monolayers

CPP 19.5: Poster

Donnerstag, 5. April 2001, 12:30–15:00, AT1

Dielectric resonance spectroscopy for the investigation of electromechanical properties of anisotropic polymers — •Harald Salhofer, Gerhard S. Neugschwandtner, Reinhard Schwödiauer, Simona Bauer-Gogonea, and Siegfried Bauer — Applied Physics, Johannes-Kepler University, Linz, Austria

Broadband dielectric spectroscopy up to the GHz region not only gives information about charge carrier and dipole relaxation processes, but also enables the determination of electromechanical properties of materials. In piezoelectric materials, electromechanical resonance modes are excited by the application of sinusoidally oscillating electric fields. The electromechanical resonance modes are displayed in sharp resonance features in the dielectric function of the piezoelectric material. The analysis of electromechanical resonance modes in the dielectric function allows for the measurement of piezoelectric tensor elements, and additionally enables the determination of several mechanical properties, such as the anisotropic sound velocity, elastic tensor elements and electromechanical coupling factors. Experimental results will be presented on ferroelectric polymers and on newly developed piezoelectric space-charge electrets. Work supported by the FWF.