Kinetic study of the solid state reaction between alpha-Fe2O3 and ZnO for zinc ferrite formation

Halikia, Iliana; Milona, Evangelia

dc.contributor.author	Halikia, Iliana	en
dc.contributor.author	Milona, Evangelia	en
dc.date.accessioned	2014-03-01T01:09:57Z
dc.date.available	2014-03-01T01:09:57Z
dc.date.issued	1994	en
dc.identifier.issn	0008-4433	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/11255
dc.relation.uri	http://www.scopus.com/inward/record.url?eid=2-s2.0-0028421061&partnerID=40&md5=5386f5398f4fbdebcb7a5f86b33c2656	en
dc.subject.classification	Metallurgy & Metallurgical Engineering	en
dc.subject.other	Approximation theory	en
dc.subject.other	Calculations	en
dc.subject.other	Calibration	en
dc.subject.other	Diffusion	en
dc.subject.other	Ferrites	en
dc.subject.other	Iron oxides	en
dc.subject.other	Low temperature operations	en
dc.subject.other	Mathematical models	en
dc.subject.other	Mixtures	en
dc.subject.other	Temperature	en
dc.subject.other	X ray analysis	en
dc.subject.other	Zinc oxide	en
dc.subject.other	Activation energy	en
dc.subject.other	Arrhenius expression	en
dc.subject.other	Molar ratio	en
dc.subject.other	Nucleation	en
dc.subject.other	Phase boundary reaction	en
dc.subject.other	Solid state reaction	en
dc.subject.other	Time	en
dc.subject.other	X ray diffraction	en
dc.subject.other	Zinc ferrite	en
dc.subject.other	Reaction kinetics	en
dc.title	Kinetic study of the solid state reaction between alpha-Fe2O3 and ZnO for zinc ferrite formation	en
heal.type	journalArticle	en
heal.language	English	en
heal.publicationDate	1994	en
heal.abstract	The solid state reaction between ferric oxide and zinc oxide to form zinc ferrite was studied considering the variables of temperature, time and molar ratio of the reactant oxides. The reaction mixtures were analysed by X-ray diffraction and the external standard method was applied to follow the reaction quantitatively. The intensity of the strongest reflections of alpha-Fe2O3 and ZnO were measured and calibration graphs, prepared for standard mixtures, were used to calculate the fraction reacted, alpha. Selection of the strongest oxide lines improved the sensitivity and lowered the detection limit of the quantitative analysis. The nucleation of zinc ferrite was retarded in reaction mixtures with an excess of ferric oxide. The presence of zinc oxide, in ratios higher than equimolar, accelerated the reaction. Reaction data were analysed using kinetic equations corresponding to models of (a) diffusion, (b) nucleation and (c) phase boundary reaction. After an initial period at low temperature, during which the interface reaction rate and diffusion through the layer product contributed comparably to the reaction rate, the reaction in equimolar mixtures was approximated by the diffusion equations. The Arrhenius expression was used to calculate the activation energy.	en
heal.publisher	Pergamon Press Inc, Tarrytown, NY, United States	en
heal.journalName	Canadian Metallurgical Quarterly	en
dc.identifier.isi	ISI:A1994NF55600002	en
dc.identifier.volume	33	en
dc.identifier.issue	2	en
dc.identifier.spage	99	en
dc.identifier.epage	109	en