Institut / Details zur Veranstaltung

01.02.: Seminar des Instituts: Dr. Xunlin Qiu (Universität Potsdam), Ferroelectrets: Heterogenous Polymer Electrets with High Electromechanical Response

Ferroelectrets are relatively new members in the family of piezo-, pyro-, and ferroelectric materials. They are non-polar polymer foams and other polymer systems with gas-filled cavities of suitable size and shape. After electrical charging, the cavities are turned into macroscopic dipoles. Ferroelectrets show high piezoelectric effects due to the high compressibility of the cavities. Thus, ferroelectrets combine some of the respective advantages of traditional ferroelectric ceramics (high piezoelectric sensitivity) and of ferroelectric polymers (flexibility and compliance). In the presentation an overview of our comprehensive studies on this new materials class of ferro- or piezoelectrets will be provided. In particular, I will discuss our original work on 1) the production and optimization of the foam or cavity structures, 2) the electrical charging of the cavities via dielectric barrier discharges (plasma discharges, which are realized by ionization of the gas inside the cavities, separation of electric charges of opposite sign and deposition of the electric charges on the internal surfaces of the cavities, 3) the detection of a polarization vs. electric field (P(E)) hysteresis behavior (typical for most piezoelectric materials, although the microscopic mechanisms can be quite different), and 4) the application-oriented improvement of the piezoelectric effects.

Ort:

Raum 0.108, Haus 28 (Institut fuer Physik)

Zeit:

16:15 Uhr