Thermodynamic assessment of the palladium–tellurium (Pd–Te) system

Among the fission products formed in nuclear fuels, the platinum-group metal palladium and the chalcogen element tellurium exhibit strong interaction. It is therefore of interest to be able to predict the chemical equilibria involving the Pd and Te fission products.A thermodynamic assessment is carried out using the Calphad (Calculation of Phase Diagram) method to investigate the behaviour of Pd–Te alloy system in nuclear fuels under irradiation and under waste disposal conditions. The Pd–Te binary description was optimized using experimental data found in literature including thermodynamic properties and phase diagram data. To validate the calculated phase diagram and thermodynamic properties, the results are compared with data from the literature. Both calculated and experimental phase diagrams and thermodynamic properties are in good agreement in the whole Pd–Te composition range.

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► A thermodynamic assessment of the Pd–Te system has been undertaken using the Calphad method.
► The Pd–Te phase diagram includes numerous intermetallic compounds which were all modelled: Pd17Te4, Pd3Te, Pd20Te7, Pd8Te3, Pd7Te3, Pd9Te4, Pd3Te2, PdTe and PdTe2.
► The Pd–Te binary description was optimized using both thermodynamic properties and phase diagram data.
► Calculated phase diagram and thermodynamic properties are in good agreement with the experimental values.