DocumentCode :
3053405
Title :
Complex permittivity spectra of several insulating polymers at electrical and THz frequencies
Author :
Ohki, Y. ; Fuse, N. ; Hikosaka, S. ; Takemura, Y. ; Mizuno, M. ; Fukunaga, K.
Author_Institution :
Dept. of Electr. Eng. & Biosci., Waseda Univ., Shinjuku, Japan
fYear :
2009
fDate :
18-21 Oct. 2009
Firstpage :
7
Lastpage :
10
Abstract :
Frequency and temperature dependencies of the real part (¿r\´) and imaginary part (¿r ") of relative complex permittivity were measured at electrical frequencies from 10-2 to 105 Hz at temperatures from -80 to 200°C for various kinds of organic insulating polymer films. Furthermore, frequency spectra were obtained at 30°C in a frequency range from 0.4 to 4.0 THz for both parts. As a result, it was found that there are significant differences in both the temperature and frequency dependencies of ¿r\´ and ¿¿", depending mainly on the polymer being polar or nonpolar. By comparing terahertz (THz) time-domain spectra obtained for various polymeric insulating films such as polyamide and poly(L-lactide), it was found that the polar polymers have one or two distinct dielectric loss peaks around 2.0 and 3.0 THz. More specifically, among the polymers examined, only polyamide has both two peaks, while poly(L-lactide) and polyethylene terephthalate have only one peak. Nonpolar polymers show no peaks. Furthermore, it has become clear that ¿r\´ approaches almost the same value of 2.3 at 3.8 THz in most polymers including polar ones. This agrees with the fact that only electronic polarization and atomic polarization associated with very light atoms such as hydrogen can participate in polarization at such high frequencies.
Keywords :
dielectric losses; dielectric thin films; insulating thin films; permittivity; polymer films; THz frequencies; atomic polarization; complex permittivity spectra; dielectric loss peaks; electrical frequencies; electronic polarization; frequency 0.4 THz to 4 THz; frequency dependencies; frequency spectra; organic insulating polymer films; polar polymers; poly(L-lactide); polyamide; polymeric insulating films; relative complex permittivity; temperature -80 C to 200 C; temperature dependencies; terahertz time-domain spectra; Dielectric losses; Dielectrics and electrical insulation; Electric variables measurement; Frequency measurement; Optical polarization; Permittivity measurement; Plastic insulation; Polymer films; Temperature dependence; Time domain analysis;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Electrical Insulation and Dielectric Phenomena, 2009. CEIDP '09. IEEE Conference on
Conference_Location :
Virginia Beach, VA
ISSN :
0084-9162
Print_ISBN :
978-1-4244-4557-8
Electronic_ISBN :
0084-9162
Type :
conf
DOI :
10.1109/CEIDP.2009.5377894
Filename :
5377894
Link To Document :
بازگشت