dc.creator | Dantas, Noelio Oliveira | |
dc.creator | Ayta, Walter Elias Feria | |
dc.creator | Silva, Anielle C A | |
dc.creator | Mamani, Nilo Francisco Cano | |
dc.creator | Rodriguez, Anselmo F R | |
dc.creator | Oliveira, Aderbal C | |
dc.creator | Garg, Vijayendra K | |
dc.creator | Morais, Paulo C | |
dc.date.accessioned | 2013-11-07T09:55:54Z | |
dc.date.accessioned | 2018-07-04T16:20:21Z | |
dc.date.available | 2013-11-07T09:55:54Z | |
dc.date.available | 2018-07-04T16:20:21Z | |
dc.date.created | 2013-11-07T09:55:54Z | |
dc.date.issued | 2012 | |
dc.identifier | SOLID STATE SCIENCES, AMSTERDAM, v. 14, n. 8, supl. 1, Part 2, pp. 1169-1174, AUG, 2012 | |
dc.identifier | 1293-2558 | |
dc.identifier | http://www.producao.usp.br/handle/BDPI/42794 | |
dc.identifier | 10.1016/j.solidstatesciences.2012.05.033 | |
dc.identifier | http://dx.doi.org/10.1016/j.solidstatesciences.2012.05.033 | |
dc.identifier.uri | http://repositorioslatinoamericanos.uchile.cl/handle/2250/1634564 | |
dc.description.abstract | Samples of 40SiO(2)center dot 30Na(2)O center dot 1Al(2)O(3)center dot(29 - x)B2O3 center dot xFe(2)O(3) (mol%), with 0.0 <= x <= 17.5, were prepared by the fusion method and investigated by electron paramagnetic resonance (EPR), optical absorption (OA) and Mossbauer spectroscopy (MS). The EPR spectra of the as-synthesized samples exhibit two well-defined EPR signals around g = 4.27 and g = 2.01 and a visible EPR shoulder around g = 6.4, assigned to isolated Fe3+ ion complexes (g = 4.27 and g = 6.4) and Fe3+-based clusters (g = 2.01). Analyses of both EPR line intensity and line width support the model picture of Fe3+-based clusters built in from two sources of isolated ions, namely Fe2+ and Fe3+; the ferrous ion being used to build in iron-based clusters at lower x-content (below about x = 2.5%) whereas the ferric ion is used to build in iron-based clusters at higher x-content (above about x = 2.5%). The presence of Fe2+ ions incorporated within the glass template is supported by OA data with a strong band around 1100 nm due to the spin-allowed E-5(g)-T-5(2g) transition in an octahedral coordination with oxygen. Additionally, Mossbauer data (isomer shift and quadrupole splitting) confirm incorporation of both Fe2+ and Fe3+ ions within the template, more likely in tetrahedral-like environments. We hypothesize that ferrous ions are incorporated within the glass template as FeO4 complex resulting from replacing silicon in non-bridging oxygen (SiO3O-) sites whereas ferric ions are incorporated as FeO4 complex resulting from replacing silicon in bridging-like oxygen silicate groups (SiO4). (C) 2012 Elsevier Masson SAS. All rights reserved. | |
dc.language | eng | |
dc.publisher | ELSEVIER SCIENCE BV | |
dc.publisher | AMSTERDAM | |
dc.relation | SOLID STATE SCIENCES | |
dc.rights | Copyright ELSEVIER SCIENCE BV | |
dc.rights | closedAccess | |
dc.subject | IRON OXIDE | |
dc.subject | GLASSES | |
dc.subject | EPR | |
dc.subject | OPTICAL ABSORPTION | |
dc.subject | MOSSBAUER SPECTROSCOPY | |
dc.title | Magnetic and optical investigation of 40SiO(2)center dot 30Na(2)O center dot 1Al(2)O(3)center dot(29-x) B2O3 center dot xFe(2)O(3) glass matrix | |
dc.type | Artículos de revistas | |