Correlation of reactivity with structural factors in a series of Fe(II) substituted cobalt ferrites

A series of powdered cobalt ferrites, CoxFe3-xO4 with 0.66≤x<1.00 containing different amounts of FeII, were synthesized by a mild procedure, and their Fe and Co site occupancies and structural characteristics were explored using X-ray anomalous scattering and the Rietveld refinement method....

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Autor principal:	Sileo, Elsa Ester
Publicado:	2006
Materias:	Cobalt ferrites Electron hopping Kinetic dissolution Rietveld method X-ray anomalous scattering Dissolution Iron compounds Molecular structure Reaction kinetics Substitution reactions Synthesis (chemical) X ray scattering Cobalt compounds
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00224596_v179_n7_p2237_Sileo http://hdl.handle.net/20.500.12110/paper_00224596_v179_n7_p2237_Sileo
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_00224596_v179_n7_p2237_Sileo
record_format	dspace
spelling	paper:paper_00224596_v179_n7_p2237_Sileo2023-06-08T14:50:54Z Correlation of reactivity with structural factors in a series of Fe(II) substituted cobalt ferrites Sileo, Elsa Ester Cobalt ferrites Electron hopping Kinetic dissolution Rietveld method X-ray anomalous scattering Dissolution Iron compounds Molecular structure Reaction kinetics Substitution reactions Synthesis (chemical) X ray scattering Cobalt ferrites Electron hopping Kinetic dissolution Rietveld method X-ray anomalous scattering Cobalt compounds A series of powdered cobalt ferrites, CoxFe3-xO4 with 0.66≤x<1.00 containing different amounts of FeII, were synthesized by a mild procedure, and their Fe and Co site occupancies and structural characteristics were explored using X-ray anomalous scattering and the Rietveld refinement method. The dissolution kinetics, measured in 0.1 M oxalic acid aqueous solution at 70 °C, indicate in all cases the operation of a contracting volume rate law. The specific rates increased with the FeII content following approximately a second-order polynomial expression. This result suggests that the transfer of FeIII controls the dissolution rate, and that the leaching of a first layer of ions CoII and FeII leaves exposed a surface enriched in slower dissolving octahedral FeIII ions. Within this model, inner vicinal lattice FeII accelerates the rate of FeIII transfer via internal electron hopping. A chain mechanism, involving successive electron transfers, fits the data very well. © 2006 Elsevier Inc. All rights reserved. Fil:Sileo, E.E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2006 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00224596_v179_n7_p2237_Sileo http://hdl.handle.net/20.500.12110/paper_00224596_v179_n7_p2237_Sileo
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Cobalt ferrites Electron hopping Kinetic dissolution Rietveld method X-ray anomalous scattering Dissolution Iron compounds Molecular structure Reaction kinetics Substitution reactions Synthesis (chemical) X ray scattering Cobalt ferrites Electron hopping Kinetic dissolution Rietveld method X-ray anomalous scattering Cobalt compounds
spellingShingle	Cobalt ferrites Electron hopping Kinetic dissolution Rietveld method X-ray anomalous scattering Dissolution Iron compounds Molecular structure Reaction kinetics Substitution reactions Synthesis (chemical) X ray scattering Cobalt ferrites Electron hopping Kinetic dissolution Rietveld method X-ray anomalous scattering Cobalt compounds Sileo, Elsa Ester Correlation of reactivity with structural factors in a series of Fe(II) substituted cobalt ferrites
topic_facet	Cobalt ferrites Electron hopping Kinetic dissolution Rietveld method X-ray anomalous scattering Dissolution Iron compounds Molecular structure Reaction kinetics Substitution reactions Synthesis (chemical) X ray scattering Cobalt ferrites Electron hopping Kinetic dissolution Rietveld method X-ray anomalous scattering Cobalt compounds
description	A series of powdered cobalt ferrites, CoxFe3-xO4 with 0.66≤x<1.00 containing different amounts of FeII, were synthesized by a mild procedure, and their Fe and Co site occupancies and structural characteristics were explored using X-ray anomalous scattering and the Rietveld refinement method. The dissolution kinetics, measured in 0.1 M oxalic acid aqueous solution at 70 °C, indicate in all cases the operation of a contracting volume rate law. The specific rates increased with the FeII content following approximately a second-order polynomial expression. This result suggests that the transfer of FeIII controls the dissolution rate, and that the leaching of a first layer of ions CoII and FeII leaves exposed a surface enriched in slower dissolving octahedral FeIII ions. Within this model, inner vicinal lattice FeII accelerates the rate of FeIII transfer via internal electron hopping. A chain mechanism, involving successive electron transfers, fits the data very well. © 2006 Elsevier Inc. All rights reserved.
author	Sileo, Elsa Ester
author_facet	Sileo, Elsa Ester
author_sort	Sileo, Elsa Ester
title	Correlation of reactivity with structural factors in a series of Fe(II) substituted cobalt ferrites
title_short	Correlation of reactivity with structural factors in a series of Fe(II) substituted cobalt ferrites
title_full	Correlation of reactivity with structural factors in a series of Fe(II) substituted cobalt ferrites
title_fullStr	Correlation of reactivity with structural factors in a series of Fe(II) substituted cobalt ferrites
title_full_unstemmed	Correlation of reactivity with structural factors in a series of Fe(II) substituted cobalt ferrites
title_sort	correlation of reactivity with structural factors in a series of fe(ii) substituted cobalt ferrites
publishDate	2006
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00224596_v179_n7_p2237_Sileo http://hdl.handle.net/20.500.12110/paper_00224596_v179_n7_p2237_Sileo
work_keys_str_mv	AT sileoelsaester correlationofreactivitywithstructuralfactorsinaseriesoffeiisubstitutedcobaltferrites
_version_	1768544307908706304

Correlation of reactivity with structural factors in a series of Fe(II) substituted cobalt ferrites

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