Thermodynamic study of the Ag-Sb-Te system with an advanced EMF method

Markus Aspiala*, Pekka Taskinen

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

4 Citations (Scopus)

Abstract

In this work, thermodynamic properties of antimony saturated AgSbTe2 (Ag0.22Sb0.28Te0.50) and silver saturated SbxTe1-x (Ag0.08Sb0.49Te0.43) have been determined by solid state EMF technique with Ag+ ion conducting beta ''-alumina electrolyte, for the first time. The measurements were done by electrochemical cells of type:

(-)Pt, AS vertical bar beta ''-alumina vertical bar Sb2Te3 + Ag2Te + SbxTe1-x, Re, Pt(+)

Over the temperature range 566

(-)Pt, Ag vertical bar beta ''-alumina vertical bar AgSbTe2 + Ag2Te + SbxTe1-x, Re, Pt(+)

Over the temperature range 620.5

The phase transition temperature, where Sb2Te3 and Ag2Te form AgSbTe2 at 101.3 kPa pressure, was found to be T = 620.5 K. Standard thermodynamic quantities of SbxTe1-x and AgSbTe2 were calculated from the results obtained as well as Gibbs energies of formation as linear functions of temperature. Each test electrode, containing 3 phases in equilibrium, was synthetized separately inside an evacuated quartz glass ampoule and quenched into ice water. The contents of the test electrodes were confirmed by SEM-EDS analysis. Also, the average solubility of substances in the test electrodes was calculated from the SEM-EDS data obtained. The parasitic thermovoltage involved with the measured EMF was determined by symmetrical cell arrangement and compensated from the experimental values. (C) 2015 Elsevier Ltd. MI rights reserved.

Original languageEnglish
Pages (from-to)261-266
Number of pages6
JournalJournal of Chemical Thermodynamics
Volume93
DOIs
Publication statusPublished - Feb 2016
MoE publication typeA1 Journal article-refereed

Keywords

  • Ag-Sb-Te system
  • AgSbTe2
  • beta ''-Alumina
  • EMF technique
  • Gibbs energy of formation
  • Phase transition temperature

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