Piezoelectricity analysis in VDF-TrFE copolymer films using the pressure wave propagation method

Author

Laburthe-Tolra, C. ; Alquie, C. ; Lewiner, J.

Author_Institution

Ecole Superieure de Phys. et de Chimie Ind., Paris, France

fYear

1990

fDate

28-31 Oct 1990

Firstpage

71

Lastpage

76

Abstract

The pressure wave propagation method was used to study the polarization of VDF-TrFE (75-25%) copolymer films, by measuring the homogeneity, within the bulk of the material, of the piezoelectric coefficient and its relative amplitude. The influence of the value of the poling field and of the duration of the polarization process, associated with various thermal treatments, is investigated for 150-μm-thick films. When no thermal treatment is applied prior to the polarization process, the polarization is nonuniform at low field (0.3 MV/cm) and its buildup is rather slow. A fast response to the poling field is observed in films previously heated above the Curie point, and for applied fields equal to 0.7 MV/cm. In this case the polarization is uniform, even for low applied fields. Moreover, this polarization is very stable

Keywords

dielectric polarisation; ferroelectric materials; ferroelectric thin films; heat treatment; piezoelectricity; polymer blends; polymer films; Curie point; VDF-TrFE copolymer films; applied fields; homogeneity; piezoelectric coefficient; polarization; polarization process; poling field; pressure wave propagation method; thermal treatments; trifluoroethylene; vinylidene fluoride; Acoustic propagation; Circuits; Current measurement; Electrodes; Optical pulse generation; Piezoelectric films; Piezoelectric materials; Piezoelectric polarization; Piezoelectricity; Pressure measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrical Insulation and Dielectric Phenomena, 1990. Annual Report., Conference on

Conference_Location

Pocono Manor, PA

Type

conf

DOI

10.1109/CEIDP.1990.201322

Filename

201322