Phase relations and activities in the Co Ni O system at 1373 K

Jacob, KT and Iyengar, GNK and Srikanth, S (1986) Phase relations and activities in the Co Ni O system at 1373 K. In: Bulletin of Materials Science, 8 (1). pp. 71-79.

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Abstract

The tie-lines delineating equilibria between CoO-NiO and Co-Ni solid solutions in the ternary Co-Ni-O system at 1373 K have been determined by electron microprobe andedax point count analysis of the oxide phase equilibrated with the alloy. The oxygen potentials corresponding to the tie-line compositions have been measured using a solid oxide galvanic cell with calcia-stabilized zirconia electrolyte and Ni + NiO reference electrode. Activities in the metallic and oxide solid solution have been derived using a new Gibbs-Duhem integration technique. Both phases exhibit small positive deviations from ideality; the values ofG E/X 1 X 2 are 2640 J mol−1 for the metallic phase and 2870 J mol−1 for the oxide solid solution.

Item Type:	Journal Article
Publication:	Bulletin of Materials Science
Publisher:	Indian Academy of Sciences
Additional Information:	Copyright of this article belongs to Indian Academy of Sciences.
Keywords:	Free energy of mixing - cobalt-nickel alloys - cobalt oxide-nickel oxide solid solution;oxygen potential;solid state cell;thermodynamic properties;phase diagram; electromotive force
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	07 Dec 2011 09:10
Last Modified:	07 Dec 2011 09:10
URI:	http://eprints.iisc.ac.in/id/eprint/42574

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