Resonance characteristics and polarization profile of partially poled P(VDF-TrFE) copolymer

Bernd Ploss, H. L.W. Chan, Kin Wing Kwok, C. L. Choy

Research output: Chapter in book / Conference proceedingConference article published in proceeding or bookAcademic researchpeer-review

2 Citations (Scopus)

Abstract

Thick films of polyvinylidene fluoride/trifluoroethylene (P(VDF-TrFE) copolymer with the composition 80/20 mol-% were poled at elevated temperature. The dielectric spectrum of this film shows two resonance peaks which correspond to the fundamental and second harmonic of the thickness vibration mode. Even harmonics of the thickness mode are usually not observed as they are not coupled to the electrical excitation. Piezoelectric and pyroelectric profiling experiments using both the pressure wave propagation (PWP) method and the laser intensity modulation method (LIMM) show that the copolymer has an inhomogeneous polarization profile which leads to the observed second order harmonic. In particular, these methods indicate that an unpoled region exists near the cathode side of the sample. By fitting the observed dielectric spectrum to a model of two Lorentz oscillators, the oscillation strengths have been estimated and found to be consistent with those obtained from the appropriate Fourier coefficients of the measured pyroelectric profile.
Original languageEnglish
Title of host publicationProceedings - International Symposium on Electrets
PublisherIEEE
Pages279-284
Number of pages6
Publication statusPublished - 1 Dec 1996
Externally publishedYes
EventProceedings of the 1996 IEEE 9th International Symposium on Electrets, ISE 9 - Shanghai, China
Duration: 25 Sep 199627 Sep 1996

Conference

ConferenceProceedings of the 1996 IEEE 9th International Symposium on Electrets, ISE 9
Country/TerritoryChina
CityShanghai
Period25/09/9627/09/96

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering
  • Materials Chemistry

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