Low temperature dielectric relaxations in ZnO varistor

Tsonos, C; Kanapitsas, A; Triantis, D; Anastasiadis, C; Stavrakas, I; Pissis, P

dc.contributor.author	Tsonos, C	en
dc.contributor.author	Kanapitsas, A	en
dc.contributor.author	Triantis, D	en
dc.contributor.author	Anastasiadis, C	en
dc.contributor.author	Stavrakas, I	en
dc.contributor.author	Pissis, P	en
dc.date.accessioned	2014-03-01T01:33:43Z
dc.date.available	2014-03-01T01:33:43Z
dc.date.issued	2010	en
dc.identifier.issn	00214922	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/20552
dc.subject	Dielectric Relaxation	en
dc.subject	Low Temperature	en
dc.subject.other	Arrhenius	en
dc.subject.other	Characteristic value	en
dc.subject.other	Complex frequency	en
dc.subject.other	Davidson	en
dc.subject.other	Defects induced	en
dc.subject.other	Dielectric relaxation spectroscopy	en
dc.subject.other	Dopant impurities	en
dc.subject.other	Electronic process	en
dc.subject.other	Longitudinal optical phonon energies	en
dc.subject.other	Low temperatures	en
dc.subject.other	Native defect	en
dc.subject.other	Temperature rise	en
dc.subject.other	Thermal behaviours	en
dc.subject.other	Thermally activated	en
dc.subject.other	Transition temperature	en
dc.subject.other	ZnO	en
dc.subject.other	ZnO varistors	en
dc.subject.other	Activation energy	en
dc.subject.other	Debye temperature	en
dc.subject.other	Defects	en
dc.subject.other	Dielectric losses	en
dc.subject.other	Dielectric relaxation	en
dc.subject.other	Doping (additives)	en
dc.subject.other	Spectroscopy	en
dc.subject.other	Varistors	en
dc.subject.other	Zinc	en
dc.subject.other	Zinc oxide	en
dc.subject.other	Electron energy loss spectroscopy	en
dc.title	Low temperature dielectric relaxations in ZnO varistor	en
heal.type	journalArticle	en
heal.identifier.primary	10.1143/JJAP.49.051102	en
heal.identifier.secondary	http://dx.doi.org/10.1143/JJAP.49.051102	en
heal.publicationDate	2010	en
heal.abstract	The main purpose of this work is to study the behaviour of ZnO varistor by means of dielectric relaxation spectroscopy at the low temperature range. The complex frequency spectrum of dielectric losses has been studied in detail and analysed carefully by fitting of a sum of Havriliak- Negami expression. Three relaxation processes are studied here, exhibiting a very strong Cole-Davidson behaviour. The faster relaxation process shows an unusual thermal behaviour. Initially, its relaxation time increases as the temperature rises but later it becomes thermally activated. The transition temperature of thermal behaviour of this process was found very close to the characteristic value of 0.4θD = 160 K, where θD is the Debye temperature of ZnO. The de-activation energy of this process has been estimated by using the Arrhenius type relation to be 78 meV, a value very close to the higher longitudinal optical (LO) phonon energy in ZnO, 72 meV. This is a strong indication that the predicted Holstein transition between large to small-polaron motion should be observed in ZnO. The two remaining relaxations are electronic processes, the slower one is associated with the doubly ionised zinc interstitial Zni • •, while the other should be related to defects induced by the dopants, or of complexes of intrinsic native defect with dopant impurities. © 2010 The Japan Society of Applied Physics.	en
heal.journalName	Japanese Journal of Applied Physics	en
dc.identifier.doi	10.1143/JJAP.49.051102	en
dc.identifier.volume	49	en
dc.identifier.issue	5 PART 1	en
dc.identifier.spage	0511021	en
dc.identifier.epage	0511025	en