| People | Locations | Statistics |
|---|---|---|
| Naji, M. |
| |
| Motta, Antonella |
| |
| Aletan, Dirar |
| |
| Mohamed, Tarek |
| |
| Ertürk, Emre |
| |
| Taccardi, Nicola |
| |
| Kononenko, Denys |
| |
| Petrov, R. H. | Madrid |
|
| Alshaaer, Mazen | Brussels |
|
| Bih, L. |
| |
| Casati, R. |
| |
| Muller, Hermance |
| |
| Kočí, Jan | Prague |
|
| Šuljagić, Marija |
| |
| Kalteremidou, Kalliopi-Artemi | Brussels |
|
| Azam, Siraj |
| |
| Ospanova, Alyiya |
| |
| Blanpain, Bart |
| |
| Ali, M. A. |
| |
| Popa, V. |
| |
| Rančić, M. |
| |
| Ollier, Nadège |
| |
| Azevedo, Nuno Monteiro |
| |
| Landes, Michael |
| |
| Rignanese, Gian-Marco |
|
Bras, W.
in Cooperation with on an Cooperation-Score of 37%
Topics
Publications (13/13 displayed)
- 2018Investigating the interstellar dust through the Fe K-edgecitations
- 2016High-resolution small-angle x-ray diffraction study of long-range order in hard-sphere colloidal crystals.citations
- 2014X-ray irradiation induced reduction and nanoclustering of lead in borosilicate glasscitations
- 2014Influence of metal-support interaction on the surface structure of gold nanoclusters deposited on native SiOx/Si substratescitations
- 2013Effect of processing parameters on the morphology development during extrusion of polyethylene tape: an in-line Small-Angle X-ray Scattering (SAXS) studycitations
- 2012Tuning of the size and the lattice parameter of ion-beam synthesized Pb nanoparticles embedded in Sicitations
- 2010Synergistic reinforcement of highly oriented poly(propylene) tapes by sepiolite nanoclay:
- 2010Real-time WAXD detection of mesophase development during quenching of propene/ethylene copolymerscitations
- 2010Synergistic Reinforcement of Highly Oriented Poly(propylene) Tapes by Sepiolite Nanoclaycitations
- 2006Mesomorphism, polymorphism, and semicrystalline morphology of poly(Di-n-propylsiloxane)
- 2005Polymer processing: Using synchrotron radiation to follow structure development in commercial and novel polymer materialscitations
- 2003Early stages of crystallization in Isotactic Polypropylenecitations
- 2002A SAXS/WAXS XAFS study of crystallisation in cordierite glasscitations
Places of action
| Organizations | Location | People |
|---|
article
A SAXS/WAXS XAFS study of crystallisation in cordierite glass
Abstract
<p>New Cr X-ray absorption fine structure (XAFS) data have been combined with the results of small angle X-ray scattering (SAXS) and wide angle X-ray scattering (WAXS) experiments to probe in detail the crystallisation mechanism in cordierite (Mg<sub>2</sub>Al<sub>4</sub>Si<sub>5</sub>O<sub>18</sub> glass doped with 0.34 mol% Cr<sub>2</sub>O<sub>3</sub>. By direct comparison with chromo-aluminate spinels (MgCr<sub>2x</sub>Al<sub>2(1-x)</sub>O<sub>4</sub> Cr XAFS is used to determine the composition of the devitrified Cr species. This is identified as MgCr<sub>0.18</sub>Al<sub>1.82</sub>O<sub>4</sub>, which can be directly related to the Cr content in the starting glass and as a result the total crystalline volume in the fully developed ceramic is predicted to be 4%. In situ WAXS not only reveals the presence of the spinel phase but also a silica-rich stuffed quartz phase. This grows independently of the spinel and is probably nucleated from the glass surface. From our knowledge of the compositions of both crystalline phases we are able to deduce that the SAXS contrast between the surrounding glass and the spinel crystallites is 30 times greater than that between the quartz crystallites and the glass matrix, and therefore dominates the measured scattered intensity and the SAXS invariant that is derived from it. As a consequence we are able to show that the spinel crystalline volume fraction inherent in the SAXS is in close agreement with the 4% value obtained from the Cr XAFS. Furthermore in situ SAXS reveals the gradual development of the spinel particle size and shape during heat treatment. This is conducted in the super-cooled region just above the glass transition temperature, T<sub>g</sub>. By employing a two-step annealing process nucleation can be separated from growth and from time-resolved SAXS measurements the alumino-chromate nanocrystals are found to be closely monodispersed. Over a total time course of 600 min they grow from rough crystallites to smooth spherical particles of radius 21 ± 2 nm, with a final density of (1.2 ± 0.4) × 10<sup>21</sup> m<sup>-3</sup>. As the process of ceramic formation takes place in the viscous melt, growth is indeed found to be limited by diffusion and is complete when all the Cr is exhausted. We use this comprehensive in situ study of crystallisation in cordierite glass to demonstrate the advantages of combining SAXS, WAXS and XAFS for probing the time-resolved chemistry, the microstructure and its development from nucleation sites, that underpins the processing of nanoparticle ceramics.</p>