Open AccessStudy of intrinsic defects in ZnO varistor ceramics by dielectric spectroscopy
Author(s) -
Shengtao Li,
Pengfei Cheng,
Zhao-Lei,
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.58.523
Subject(s) - materials science , varistor , dielectric , relaxation (psychology) , ceramic , dielectric loss , dielectric spectroscopy , spectroscopy , condensed matter physics , polarization (electrochemistry) , analytical chemistry (journal) , composite material , optoelectronics , chemistry , psychology , social psychology , physics , electrode , quantum mechanics , voltage , electrochemistry , chromatography
In this paper defect structure was investigated by dielectric response of pure ZnO ceramicsbinary and multi-element ZnO-Bi2O3 based varistor ceramics with the help of broad band dielectric spectroscopy. It is found that no loss peak appears at room temperature in pure ZnO ceramicswhile there is one and two loss peaks in the binary and multi-element ZnO-Bi2O3 based varistor ceramicsrespectively. According to relaxation polarization theory and electronic relaxation theoryit is obtained that electronic relaxation process is equivalent to relaxation polarization in dielectric spectroscopy and the characteristic peak near 105Hz at room temperature arises from relaxation process of electrons trapped by oxygen vacancies and zinc interstitials. Based on the difference in the dependence of the two loss peaks on the temperature and the atmosphere of heat treatmentaging mechanism is explained as the desorption of oxygen.