dc.contributorUniversidade Estadual Paulista (UNESP)
dc.creatorBrito, G. E. S.
dc.creatorSantilli, Celso Valentim
dc.creatorPulcinelli, Sandra Helena
dc.creatorCraievich, A. F.
dc.date2014-05-27T11:18:15Z
dc.date2016-10-25T18:14:33Z
dc.date2014-05-27T11:18:15Z
dc.date2016-10-25T18:14:33Z
dc.date1997-08-01
dc.date.accessioned2017-04-06T00:49:56Z
dc.date.available2017-04-06T00:49:56Z
dc.identifierJournal of Non-Crystalline Solids, v. 217, n. 1, p. 41-47, 1997.
dc.identifier0022-3093
dc.identifierhttp://hdl.handle.net/11449/65154
dc.identifierhttp://acervodigital.unesp.br/handle/11449/65154
dc.identifier10.1016/S0022-3093(97)00137-3
dc.identifierWOS:A1997XV21100005
dc.identifier2-s2.0-0031549247
dc.identifierhttp://dx.doi.org/10.1016/S0022-3093(97)00137-3
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/886904
dc.descriptionThe small-angle X-ray scattering (SAXS) technique was used to study the porosity which develops in Cu(II)-doped SnO2 monolithic xerogels during crystallization. The influence of the upper temperature of heat-treatment and of Cu(II) content on the structure was determined. Previous studies of the porosity in undoped SnO2 samples treated at temperatures ranging from 300 up to 600°C demonstrated the existence of a bimodal size distribution (one distribution was due to intra-aggregate and the other to inter-aggregate pores). However, the SAXS data from Cu(II)-doped samples heated to 500°C had a single mode distribution due only to inter-aggregate pores. Doped samples isothermically treated at 500°C were studied by the in situ SAXS technique. The time evolution of the scattering intensity function, or structure function of the porous material, exhibits a dynamical scaling property. The asymptotic behavior at high q (wave numbers) of the scaled function and consequently the nature and morphology of the porosity interface are a function of Cu(II) content. The kinetic exponents predicted by the statistical theory for the structure function suggest that the mechanism of porosity coarsening is controlled by surface diffusion. © 1997 Elsevier Science B.V.
dc.descriptionConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
dc.languageeng
dc.relationJournal of Non-Crystalline Solids
dc.rightsinfo:eu-repo/semantics/closedAccess
dc.subjectCrystallization
dc.subjectDiffusion in solids
dc.subjectDoping (additives)
dc.subjectHeat treatment
dc.subjectInterfaces (materials)
dc.subjectMorphology
dc.subjectParticle size analysis
dc.subjectPorosity
dc.subjectPorous materials
dc.subjectReaction kinetics
dc.subjectX ray analysis
dc.subjectMonolithic xerogels
dc.subjectSmall angle X ray scattering (SAXS)
dc.subjectSol-gels
dc.titleSAXS measurements of the porosity in Cu(II)-doped SnO2 xerogels during crystallization
dc.typeOtro


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