Thermodynamic partial properties of Na2O in Nasicon solid solution, Na1+xZr2SixP3-xO12

Kale, GM and Jacob, KT (1989) Thermodynamic partial properties of Na2O in Nasicon solid solution, Na1+xZr2SixP3-xO12. In: Journal of Materials Research, 4 (2). pp. 417-422.

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Abstract

The thermodynamic activity of sodium oxide (Na2O) in the Nasicon solid solution series, Na1+xZr2SixO12, has been measured in the temperature range 700�1100 K using solid state galvanic cells: Pt|CO2 + O2|Na2CO3?Na1+xZr2SixP3-xO12?(Y2O3)ZrO2?In + In2O3|Ta, Pt for 1 = ? = 2.5, and Pt?CO2 + O2?Na2CO3?ß-alumina?Na1+xZr2SixP3-xO12?Ar + O2?Pt for x = 0, 0.5, 2.5, and 3. The former cell, where the Nasicon solid solution is used as an electrolyte along with yttria-stabilized zirconia, is well suited for Nasicon compositions with high ionic conductivity. In the latter cell, ß-alumina is used as an electrolyte and the Nasicon solid solution forms an electrode. The chemical potential of Na2O is found to increase monotonically with x at constant temperature. The partial entropy of Na2O decreases continuously with x. However, the partial enthalpy exhibits a maximum at x = 2. This suggests that the binding energy is minimum at the composition where ionic conductivity and cell volume have maximum values.

Item Type:	Journal Article
Publication:	Journal of Materials Research
Publisher:	The Materials Research Society
Additional Information:	Copyright of this article belongs to The Materials Research Society.
Department/Centre:	Division of Mechanical Sciences > Materials Engineering (formerly Metallurgy)
Date Deposited:	20 Oct 2010 05:37
Last Modified:	20 Oct 2010 05:37
URI:	http://eprints.iisc.ac.in/id/eprint/33310

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