dc.contributor | Universidade Estadual Paulista (UNESP) | |
dc.creator | Brito, G. E. S. | |
dc.creator | Santilli, Celso Valentim | |
dc.creator | Pulcinelli, Sandra Helena | |
dc.creator | Craievich, A. F. | |
dc.date | 2014-05-27T11:18:15Z | |
dc.date | 2016-10-25T18:14:33Z | |
dc.date | 2014-05-27T11:18:15Z | |
dc.date | 2016-10-25T18:14:33Z | |
dc.date | 1997-08-01 | |
dc.date.accessioned | 2017-04-06T00:49:56Z | |
dc.date.available | 2017-04-06T00:49:56Z | |
dc.identifier | Journal of Non-Crystalline Solids, v. 217, n. 1, p. 41-47, 1997. | |
dc.identifier | 0022-3093 | |
dc.identifier | http://hdl.handle.net/11449/65154 | |
dc.identifier | http://acervodigital.unesp.br/handle/11449/65154 | |
dc.identifier | 10.1016/S0022-3093(97)00137-3 | |
dc.identifier | WOS:A1997XV21100005 | |
dc.identifier | 2-s2.0-0031549247 | |
dc.identifier | http://dx.doi.org/10.1016/S0022-3093(97)00137-3 | |
dc.identifier.uri | http://repositorioslatinoamericanos.uchile.cl/handle/2250/886904 | |
dc.description | The 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.description | Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) | |
dc.language | eng | |
dc.relation | Journal of Non-Crystalline Solids | |
dc.rights | info:eu-repo/semantics/closedAccess | |
dc.subject | Crystallization | |
dc.subject | Diffusion in solids | |
dc.subject | Doping (additives) | |
dc.subject | Heat treatment | |
dc.subject | Interfaces (materials) | |
dc.subject | Morphology | |
dc.subject | Particle size analysis | |
dc.subject | Porosity | |
dc.subject | Porous materials | |
dc.subject | Reaction kinetics | |
dc.subject | X ray analysis | |
dc.subject | Monolithic xerogels | |
dc.subject | Small angle X ray scattering (SAXS) | |
dc.subject | Sol-gels | |
dc.title | SAXS measurements of the porosity in Cu(II)-doped SnO2 xerogels during crystallization | |
dc.type | Otro | |