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DF: Dielektrische Festkörper

DF 7: Poster

DF 7.3: Poster

Mittwoch, 26. März 2003, 14:30–18:00, P2a

Dielectric resonance spectroscopy on ferroelectric polymers and internally charged, cellular polymers (No-dqferroelectretsNo-dq) — •Mario Dansachmüller, Harald Salhofer, Simona Bauer-Gogonea, and Siegfried Bauer — Johannes-Kepler University, Soft Matter Physics, Altenbergerstr. 69, Linz, Austria

Broadband dielectric spectroscopy is a well established tool for the investigation of dipolar relaxation processes in polymers. In poled polymers exhibiting piezoelectricity, dielectric resonance spectroscopy (DRS) can be used to determine not only electrical, but also mechanical, acoustical and electromechanical material properties, by analysing piezoelectric resonances in dielectric spectra. In this contribution, we have employed DRS to the study of ferroelectric polymers and internally charged, cellular polymers. Due to unexpected similarities to ferroelectric materials, the concept of No-dqferroelectretNo-dq has been introduced for this novel class of nonpolar polymers. For No-dqferroelectretsNo-dq we will show that DRS is most suitable for the investigation of acoustical coupling effects of cellular polymer films with different media, e.g. water and air below and above ambient pressure. Water coupling results in a strong loading of the cellular polymers and leads to a strong shift of the piezoelectric resonances to lower frequencies. Air coupling at different pressures reveals the importance of the voids in cellular No-dqferroelectretNo-dq polymers for the piezoelectric resonances.