Solution decomposition of the layered double hydroxide of Co with Fe: Phase segregation of normal and inverse spinels

Britto, Sylvia and Kamath, Vishnu P and Ravishankar, N (2008) Solution decomposition of the layered double hydroxide of Co with Fe: Phase segregation of normal and inverse spinels. In: Journal of Colloid and Interface Science, 325 (2). pp. 419-424.

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Abstract

The nitrate-intercalated layered double hydroxide of Co with Fe decomposes on hydrothermal treatment to yield an oxide residue at a temperature as low as $180^o C$. The oxide product is phase segregated into a $Co_3O_{4}$-type normal spinel and a $CoFe_2O_{4}$-type inverse spinel. Phase segregation is facilitated as decomposition in a solution medium takes place by dissolution of the precursor hydroxide followed by reprecipitation of the oxide phases. In contrast, thermal decomposition takes place at $400^o C$. This temperature is inadequate to induce diffusion in the solid state whereby phase segregation into the thermodynamically stable individual spinels is suppressed. The result is a single-phase metastable mixed spinel oxide. This is rather uncommon in that a hydrothermal treatment yields thermodynamically stable products where as thermal decomposition yields a metastable product.

Item Type:	Journal Article
Publication:	Journal of Colloid and Interface Science
Publisher:	Elsevier
Additional Information:	Copyright of this article belongs to Elsevier.
Keywords:	Layered double hydroxides;Solution decomposition;Inverse spinel.
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	13 Oct 2008 09:11
Last Modified:	19 Sep 2010 04:50
URI:	http://eprints.iisc.ac.in/id/eprint/15996

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