Crystallization of iron-containing Si-Al-Mg-O glasses under laser floating zone conditions

authors	Ferreira, NM; Kovalevsky, AV; Waerenborgh, JC; Quevedo-Reyes, M; Timopheev, AA; Costa, FM; Frade, JR
nationality	International
journal	JOURNAL OF ALLOYS AND COMPOUNDS
author keywords	Laser floating zone; Mossbauer spectroscopy; Iron oxide; Aluminosilicate; Glass crystallization
keywords	SODIUM-SILICATE GLASSES; ION DOPED MULLITE; X-RAY-DIFFRACTION; MOSSBAUER-SPECTROSCOPY; ALUMINOSILICATE GLASSES; SUPERCONDUCTING FIBERS; MELTS; METAL; MGO-AL2O3-SIO2; OXIDATION
abstract	The glass system MgO-Al2O3-SiO2-FeOy has been mentioned as possible electrolyte for pyroelectrolysis of iron. This work was focused on the study of crystallization behaviour of the iron-containing Al-Mg-Si-O glass system under laser floating zone (LFZ) to identify expected changes occurring under freeze lining or other high temperature gradients at large industrial scale. Lower iron content and faster fibre growth were found favourable for the formation of isolated iron cations in the glass after cooling. The crystallization process, accompanied with separation of mullite and cordierite-type phases, is strongly affected by the formation of nanosized iron-containing clusters, confirmed by Mossbauer and EPR spectroscopies. LFZ method shows good prospects for studying crystallization/vitrification mechanisms in silicate-based glasses with additions of redox-active cations, by providing flexibility in tuning their oxidation state and attaining frozen-in conditions. (C) 2014 Elsevier B. V. All rights reserved.
publisher	ELSEVIER SCIENCE SA
issn	0925-8388
year published	2014
volume	611
beginning page	57
ending page	64
digital object identifier (doi)	10.1016/j.jallcom.2014.05.118
web of science category	Chemistry, Physical; Materials Science, Multidisciplinary; Metallurgy & Metallurgical Engineering
subject category	Chemistry; Materials Science; Metallurgy & Metallurgical Engineering
unique article identifier	WOS:000338932400011