Thermodynamic properties of strontium titanates Sr2TiO4, Sr3Ti2O7, Sr4Ti3O10, and SrTiO3

Jacob, KT and Rajitha, G (2011) Thermodynamic properties of strontium titanates Sr2TiO4, Sr3Ti2O7, Sr4Ti3O10, and SrTiO3. In: Journal of Chemical Thermodynamics, The, 43 (1). pp. 51-57.

PDF Thermodynamic.pdf - Published Version Restricted to Registered users only Download (630kB) | Request a copy

Abstract

The chemical potentials of SrO in two-phase fields (TiO2 + SrTiO3) (SrTiO3 + Sr4Ti3O10) (Sr4Ti3O10 + Sr3Ti2O7) and (Sr3Ti2O7 + Sr2TiO4) of the pseudo-binary system (SrO + TiO2) have been measured in the temperature range (900 to 1250) K relative to pure SrO as the reference state using solid-state galvanic cells incorporating single crystal SrF2 as the electrolyte The cells were operated under pure oxygen at ambient pressure The standard Gibbs free energies of formation of strontium titanates SrTiO3 Sr4Ti3O10 Sr3Ti2O7 and Sr2TiO4 from their component binary oxides were derived from the reversible electromotive force (EMF) of the cells For the formation of the four compounds from their component oxides TiO2 with rutile structure and SrO the standard Gibbs free energy changes are given by Delta G((ox))(SrTiO3) +/- 89/(J mol(-1)) = -121878 + 3 881(T/K) Delta G((ox))(Sr4Ti3O10) +/- 284/(J mol(-1)) = -409197 + 14 749(T/K) Delta G((ox))(Sr3Ti2O7) +/- 190/(J mol(-1)) = -285827 + 10 022(T/K) Delta G((ox))(Sr2TiO4) +/- 110/(J mol(-1))= -159385 + 3 770(T/K) The reference state for solid TiO2 is the rutile form The results of this study are in good agreement with Gibbs free energy of formation data reported in the literature for SrTiO3 but differ significantly with data for Sr4Ti3O10 For Si3Ti2O7 and Si2TiO4 experimental measurements are not available in the literature for direct comparison with the results obtained in this study (C) 2010 Elsevier Ltd All rights reserved

Item Type:	Journal Article
Publication:	Journal of Chemical Thermodynamics, The
Publisher:	Elsevier Science
Additional Information:	Copyright of this article belongs to Elsevier Science.
Keywords:	Strontium titanates; Gibbs free energy; Enthalpy; Entropy; Thermodynamic properties; EMF technique
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	21 Dec 2010 08:41
Last Modified:	21 Dec 2010 08:41
URI:	http://eprints.iisc.ac.in/id/eprint/34565

Actions (login required)

View Item