TSDC study on VDF/TrFE copolymers

Author

Faria, Roberto M. ; Neto, Joao M Guimaraes ; Figueiredo, Mariangola T.

Author_Institution

Inst. de Fisica e Quimica de Sao Carlos, Brazil

fYear

1991

fDate

25-27 Sep 1991

Firstpage

483

Lastpage

488

Abstract

TSDC measurements were carried out with samples of 60:40 and 70:30 molar ratios of VDF/TrFE (vinylidene fluoride-trifluoroethylene) copolymers. The 60(VDF):40(TrFE) copolymer presented a current peak around 90°C, associated with its ferroelectric-to-paraelectric (F-P) transition. The 70:30 copolymer also presented the F-P peak and, in addition, another peak at a lower temperature, identified as a phase transition between two ferroelectric phases. A model combining fast and slow polarization processes was developed to explain the TSDC curves. The fast process was connected to the phase transition, and the slow one was composed of the thermal depolarization of dipolar units of the β-phase crystallites and the variation of the pyroelectric current

Keywords

dielectric polarisation; electrets; ferroelectric materials; ferroelectric transitions; polymer blends; thermally stimulated currents; TSDC; VDF/TrFE copolymers; current peak; electret; fast polarisation; ferroelectric-to-paraelectric; phase transition; slow polarization; thermal depolarization; vinylidene fluoride-trifluoroethylene; Cooling; Crystallization; Dielectric measurements; Ferroelectric materials; Heating; Noise measurement; Phase measurement; Polarization; Pyroelectricity; Temperature measurement;

fLanguage

English

Publisher

ieee

Conference_Titel

Electrets, 1991. (ISE 7) Proceedings., 7th International Symposium on (Cat. No.91CH3029-6)

Conference_Location

Berlin

Print_ISBN

0-7803-0112-9

Type

conf

DOI

10.1109/ISE.1991.167260

Filename

167260