Determination of the enthalpies of sublimation and evaporation from thermogravimetric data: Application to metalorganic complexes of Al and Cr

Gairola, A and Kunte, GV and Umarji, AM and Shivashankar, SA (2009) Determination of the enthalpies of sublimation and evaporation from thermogravimetric data: Application to metalorganic complexes of Al and Cr. In: Thermochimica Acta, 488 (1-2). pp. 17-20.

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Abstract

A series of bimetallic acetylacetonate (acac) complexes, AlxCr1-x(acac)(3), 0 <= x <= 1, have been synthesized for application as precursors for the CVD Of Substituted oxides, such as (AlxCr1-x)(2)O-3. Detailed thermal analysis has been carried out on these complexes, which are solids that begin subliming at low temperatures, followed by melting, and evaporation from the melt. By applying the Langmuir equation to differential thermogravimetry data, the vapour pressure of these complexes is estimated. From these vapour pressure data, the distinctly different enthalpies of sublimation and evaporation are calculated, using the Clausius-Clapeyron equation. Such a determination of both the enthalpies of sublimation and evaporation of complexes, which sublime and melt congruently, does not appear to have been reported in the literature to date.

Item Type:	Journal Article
Publication:	Thermochimica Acta
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science .
Keywords:	apour pressure;Enthalpy;Sublimation; Melting;Single source precursor;Langmuir equation.
Department/Centre:	Division of Chemical Sciences > Materials Research Centre
Date Deposited:	01 Jun 2009 05:47
Last Modified:	19 Sep 2010 05:31
URI:	http://eprints.iisc.ac.in/id/eprint/20021

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