Thermal decomposition of rare-earth trioxalatocobaltates

Usha, MG and Subba Rao, M and Narayanan Kutty, TR (1981) Thermal decomposition of rare-earth trioxalatocobaltates. In: Advertisement Thermochimica Acta, 43 (1). pp. 35-47.

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Abstract

The thermal decomposition of rare-earth trioxalatocobaltates LnCo(C2O4)3 · x H2O, where Ln = La, Pr, Nd, has been studied in flowing atmospheres of air/oxygen, argon/ nitrogen, carbon dioxide and a vacuum. The compounds decompose through three major steps, viz. dehydration, decomposition of the oxalate to an intermediate carbonate, which further decomposes to yield rare-earth cobaltite as the final product. The formation of the final product is influenced by the surrounding gas atmosphere. Studies on the thermal decomposition of photodecomposed lanthanum trioxalatocobaltate and a mechanical mixture of lanthanum oxalate and cobalt oxalate in 1 : 2 molar ratio reveal that the decomposition behaviour of the two samples is different. The drawbacks of the decomposition scheme proposed earlier have been pointed out, and logical schemes based on results obtained by TG, DTA, DTG, supplemented by various physico-chemical techniques such as gas and chemical analyses, IR and mass spectroscopy, surface area and magnetic susceptibility measurements and X-ray powder diffraction methods, have been proposed for the decomposition in air of rare-earth trioxalatocobaltates as well as for the photoreduced lanthanum salt and a mechanical mixture of lanthanum and cobalt oxalates.

Item Type:	Journal Article
Publication:	Advertisement Thermochimica Acta
Publisher:	Elsevier B.V.
Additional Information:	Copyright of this article belongs to Elsevier B.V.
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry
Date Deposited:	23 Jan 2010 07:32
Last Modified:	19 Sep 2010 05:48
URI:	http://eprints.iisc.ac.in/id/eprint/23899

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