Open AccessDielectric loss of ZnO varistor ceramics by variable temperature spectroscopy
Author(s) -
Pengfei Cheng,
Shengtao Li,
Jianying Li
Publication year - 2009
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.58.5721
Subject(s) - materials science , dielectric , dielectric loss , ceramic , thermionic emission , atmospheric temperature range , polarization (electrochemistry) , varistor , spectral line , relaxation (psychology) , dipole , analytical chemistry (journal) , electron , optoelectronics , composite material , voltage , chemistry , physics , psychology , social psychology , organic chemistry , chromatography , astronomy , meteorology , quantum mechanics
In this paper the dielectric spectra of ZnO varistor ceramic were measured by Novocontrol wide band dielectric spectrometer in the temperature range of -100 ℃—20 ℃ and frequency range of 10-2—106 Hz. It is found that the activation energy is 0.26 and 0.36 eV respectively. After careful analysis of the measurement conditions quantitative calculation results and other phenomena three relaxations of cathode electron injection dipole polarization and interface polarization are discarded. Thermally stimulated currentTSC has three peaks of which the higher temperature peak comes from thermionic polarization introduced by TSC itself and other two peaks correspond to the characteristic loss peaks in dielectric spectra. Therefore it is concluded that the characteristic loss peaks of ZnO ceramics originate from electronic relaxation of intrinsic defects.