A computational investigation of cation ordering phenomena in the binary spinel system MgAl2O4-FeAl2O4

Palin, E. J. and Harrison, R. J. (2007) A computational investigation of cation ordering phenomena in the binary spinel system MgAl2O4-FeAl2O4. Mineral Mag, 71 (6). pp. 611-624. DOI https://doi.org/10.1180/minmag.2007.071.6.611

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Abstract

The systematics of cation ordering in binary spinel solid solutions have been investigated using an interatomic potential model combined with Monte Carlo simulations. The formalism to describe a system containing three cation species ordering over two non-equivalent sub-lattices is developed and the method applied to the MgAl2O4-FeAl2O4 binary solid solution. Our results compare favourably with experimental measurements of site-occupancy data, although the experiments display a slightly larger degree of non-ideality than the simulations. A possible kinetic origin of the non-ideal behaviour was examined by performing simulations in which only exchange of Mg and Fe2+ between tetrahedral and octahedral sites was permitted below the Al-blocking temperature of 1160 K. This approach improves the agreement with the experimental site occupancies, and suggests that the blocking temperature for moving Mg and Fe2+ between tetrahedral and octahedral sites is significantly lower than for moving Al.

Item Type:	Article
Uncontrolled Keywords:	08AREP; IA57;
Subjects:	03 - Mineral Sciences
Divisions:	03 - Mineral Sciences
Journal or Publication Title:	Mineral Mag
Volume:	71
Page Range:	pp. 611-624
Identification Number:	https://doi.org/10.1180/minmag.2007.071.6.611
Depositing User:	Sarah Humbert
Date Deposited:	20 May 2009 13:26
Last Modified:	23 Jul 2013 09:54
URI:	http://eprints.esc.cam.ac.uk/id/eprint/992

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