TY - JOUR
T1 - Charge transport and electrode polarization in epoxy resin at high temperatures
AU - Tian, Fuqiang
AU - Ohki, Yoshimichi
PY - 2014/1/29
Y1 - 2014/1/29
N2 - Complex permittivity spectra were measured for epoxy resin at various temperatures and numerically fitted to theories of electrode polarization (EP) and ac conduction. Complex permittivity at high temperatures fits the Cole-Cole relation for EP well, with the shape parameter relating to the electrode blockage coefficient for ions. The Debye length, ion density and mobility, hopping rate and distance, and other parameters controlling the charge transport can be obtained. Both the density and mobility of ions are thermally activated, and the sum of their activation energies is nearly the same as the activation energy of ac conductivity. It is indicated that the theory of power-law frequency response as a result of short-range hopping of ions is an extension of the EP theory above its peak frequency. On the other hand, the relaxation of ac conduction revealed by electric modulus and that of EP appearing at low frequencies are due to long-range hopping of ions. It is demonstrated that data fitting of complex permittivity to the theories of EP and ac conduction in combination with the electric modulus analysis is effective to estimate various characteristic parameters of charge transport.
AB - Complex permittivity spectra were measured for epoxy resin at various temperatures and numerically fitted to theories of electrode polarization (EP) and ac conduction. Complex permittivity at high temperatures fits the Cole-Cole relation for EP well, with the shape parameter relating to the electrode blockage coefficient for ions. The Debye length, ion density and mobility, hopping rate and distance, and other parameters controlling the charge transport can be obtained. Both the density and mobility of ions are thermally activated, and the sum of their activation energies is nearly the same as the activation energy of ac conductivity. It is indicated that the theory of power-law frequency response as a result of short-range hopping of ions is an extension of the EP theory above its peak frequency. On the other hand, the relaxation of ac conduction revealed by electric modulus and that of EP appearing at low frequencies are due to long-range hopping of ions. It is demonstrated that data fitting of complex permittivity to the theories of EP and ac conduction in combination with the electric modulus analysis is effective to estimate various characteristic parameters of charge transport.
KW - Epoxy resin
KW - charge transport
KW - complex permittivity
KW - electrode polarization
UR - http://www.scopus.com/inward/record.url?scp=84892419515&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84892419515&partnerID=8YFLogxK
U2 - 10.1088/0022-3727/47/4/045311
DO - 10.1088/0022-3727/47/4/045311
M3 - Article
AN - SCOPUS:84892419515
VL - 47
JO - Journal Physics D: Applied Physics
JF - Journal Physics D: Applied Physics
SN - 0022-3727
IS - 4
M1 - 045311
ER -