Rhombic-shaped nanodomains in columbite driven by contrasting cation order

Tarantino, Serena C. and Zema, Michele and Capitani, Giancarlo and Scavini, Marco and Ghigna, Paolo and Brunelli, Michela and Carpenter, Michael A. (2011) Rhombic-shaped nanodomains in columbite driven by contrasting cation order. American Mineralogist, 96 (2-3). pp. 374-382. DOI 10.2138/am.2011.3571

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Abstract

Transient (non-equilibrium) microstructures in crystals may arise in an order-disorder phase transition that generates lattice strain. A two-phase field can develop if fluctuations of the order parameter lead to nucleation of an ordered phase in a disordered matrix, as we describe here for columbite. Synchrotron X-ray diffraction and transmission electron microscopy show that ordering in columbite involves two discrete phases with different degree of order but the same composition. A highly unusual distribution of ordered rhombic-shaped domains within a disordered matrix establishes on a nanometer scale and remains relatively stable over a prolonged period of annealing. Progressive ordering takes place within the ordered domains and the disordered matrix but the domains maintain more or less constant shape and distribution. We speculate that a new family of such microstructures could develop in other oxide phases with cation ordering transitions that are strongly first order in character. Long-term stability of such microstructures and their dependence on strain could open up the possibility of engineering the properties of crystals containing a percolating disordered matrix with ordered nanodomains of controlled dimensions.

Item Type:	Article
Uncontrolled Keywords:	2011AREP; IA62;
Subjects:	03 - Mineral Sciences
Divisions:	03 - Mineral Sciences
Journal or Publication Title:	American Mineralogist
Volume:	96
Page Range:	pp. 374-382
Identification Number:	10.2138/am.2011.3571
Depositing User:	Sarah Humbert
Date Deposited:	25 Mar 2011 16:25
Last Modified:	23 Jul 2013 10:02
URI:	http://eprints.esc.cam.ac.uk/id/eprint/2039

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