Thermodynamic stability of CaThF6(cr) by transpiration and e.m.f. techniques

  • Sumanta Mukherjee
  • Rimpi Dawar
  • S. Phapale
  • S. Dash
  • R. MishraEmail author


In the present paper, we report the standard molar Gibbs energy of formation for CaThF6 measured by gas equilibration and e.m.f. methods. The HF(g) vapour pressure over the equilibrium reaction: \({\text{CaThF}}_{6} \left( {\text{cr}} \right) + 2 {\text{H}}_{ 2} {\text{O}}\left( {\text{g}} \right) = {\text{CaF}}_{2} \left( {\text{cr}} \right) + {\text{ThO}}_{2} \left( {\text{cr}} \right) + 4{\text{HF}}\left( {\text{g}} \right)\) has been measured using transpiration technique. The above reaction mechanism has been established employing TG and XRD techniques. A fluoride e.m.f. cell: (−)Pt, CaF2(cr) + ThOF2(cr) + CaThF6(cr) |CaF2(cr)| NiO(cr) + NiF2(cr), Pt(+) has been constructed to measure Gibbs energy of formation of CaThF6 (cr) using CaF2 (cr) as a solid electrolyte. The isobaric heat capacity \({\text{Cp}}_{\text{m}}^{{\circ }} \left( T \right)\) of the compound has been measured using differential scanning calorimetric technique. Based on the experimental results, thermodynamic functions for CaThF6 have been generated.


CaThF6 Vapour pressure EMF method Gibbs energy Heat capacity Thermodynamic function 



Authors thank Mr. Mohsin Jafar and Dr. S. N. Achary of Chemistry Division, BARC, for their help in XRD data analysis. The authors express their sincere gratitude to Smt. Akanksha Samanta of PIED, BARC, for her help in TG-MS analysis.


  1. 1.
    Macpherson HG. Molten-salt reactors. In: Proceedings of the international conference on the constructive uses of atomic energy, Washington, DC, November 1968, American Nuclear Society; 1969 March.Google Scholar
  2. 2.
    McCoy E, Weir JR. Materials development for molten salt breeder reactors, ORNL-TM1854. Oak Ridge National Laboratory; 1967 June.Google Scholar
  3. 3.
    Kasten PR. Safety program for molten-salt breeder reactors. ORNL-TM-1858, Oak Ridge National Laboratory. 9 June 1967; 1967.Google Scholar
  4. 4.
    Delpech S, Merle-Lucotte E, Heuer D, Allibert M, Ghetta V, Le-Brun C, Doligez X, Picard G. Reactor physic and reprocessing scheme for innovative Molten Salt Reactor system. J Fluorine Chem. 2009;130:11.CrossRefGoogle Scholar
  5. 5.
    Nuttin A, Heuer D, Billebaud A, Brissot R, Le Brun C, Liatard E, Loiseaux JM, Mathieu L, Meplan O, Merle-Lucotte E, Nifenecker H, Perdu F, David S. Potential of thorium molten salt reactors: detailed calculations and concept evolution with a view to large scale energy production. Prog Nucl Energy. 2005;46:77.CrossRefGoogle Scholar
  6. 6.
    Mathieu L, Heuer D, Brissot R, Garzenne C, Le Brun C, Lecarpentier D, Liatard E, JLoiseaux JM, Mèplan O, Merle-Lucotte E, Nuttin A, Walle E, Wilson J. The thorium molten salt reactor: moving on from the MSBR. Prog Nucl Energy. 2006;48:664.CrossRefGoogle Scholar
  7. 7.
    Perry AM, Bauman HF. Reactor physics and fuel cycle analysis. Nucl Appl Technol. 1970;8:208.CrossRefGoogle Scholar
  8. 8.
    Capelli E, Beneš O, Konings RJM. Thermodynamic assessment of the LiF–NaF–BeF2–ThF4–UF4 system. J Nucl Mater. 2014;449:111.CrossRefGoogle Scholar
  9. 9.
    Beneš O, Konings RJM. Thermodynamic characterization of salt components for molten salt reactor fuel. J Chem Therm. 2009;41:1086.CrossRefGoogle Scholar
  10. 10.
    Renault C, Delpech S, Merle-Lucotte E, Konings R, Hron M, Ignatiev V. The molten salt reactor (MSR)-R&D status and perspectives in Europe. FISA 2009, Prague, 22–24 June 2009; 2009.Google Scholar
  11. 11.
    Renault C, Horn M, Holcomb DE. Proceedings: GIF symposium, Paris, France, Sep. 9–10, 2009. Issy-les-Moulineaux, France: OECD Nuclear Energy Agency; 2009.Google Scholar
  12. 12.
    Capelli E, Beneš O, Raison PE, Beilmann M, Kunzel C, Konings RJM. Thermodynamic Investigation of the CaF2–ThF4 and the LiF–CaF2–ThF4 Systems. J Chem Eng Data. 2015;60:3166.CrossRefGoogle Scholar
  13. 13.
    Zachariasen WH. Crystal chemical studies of the 5f-series of elements. XII. New compounds representing known structure types. Acta Crystallogr. 1949;2:388.CrossRefGoogle Scholar
  14. 14.
    Keller C, Salzer M. Ternäre fluoride des typs MeIIMeIVF6 mit LaF3-struktur. Inorg Nucl Chem. 1967;29:2925.CrossRefGoogle Scholar
  15. 15.
    Capelli E, Beneš O, Colle JY, Konings RJM. Determination of the thermodynamic activities of LiF and ThF4 in the LixTh1−xF4-3x liquid solution by Knudsen effusion mass spectrometry. Phys Chem Chem Phys. 2015;17:30110.CrossRefPubMedGoogle Scholar
  16. 16.
    Dharwadkar SR, Kerkar AS, Samant MS. A micro thermogravimetric system for the measurement of vapor-pressure by a transpiration method. Thermochim Acta. 1993;217:175.CrossRefGoogle Scholar
  17. 17.
    Sahoo DK, Thakur S, Mishra R. Determination of thermodynamic stability of neodymium chloride hydrates (NdCl3·xH2O) by dynamic transpiration method. J Therm Anal Calorim. 2016;126(3):1407.CrossRefGoogle Scholar
  18. 18.
    Kubaschewski O, Alcock CB, Spencer PJ. Metallurgical thermochemistry. 6th ed. Oxford: Pergamon; 1993.Google Scholar
  19. 19.
    Preston-Thomas H. The international temperature scale of 1990 (ITS-90). Metrologia. 1990;27:3.CrossRefGoogle Scholar
  20. 20.
    Prasad R, Dash Smruti, Parida SC, Singh Ziley, Venugopal V. Thermodynamic studies on SrThO3(s). J Nucl Mater. 2003;312:1.CrossRefGoogle Scholar
  21. 21.
    Rodriguez-Carvajal J. Fullprof 2000: a program for Rietveld, profile matching and integrated intensity refinements for X-ray and neutron data, version 1.6. Laboratoire Leon Brillouin, Gifsur Yvette, France; 2000.Google Scholar
  22. 22.
    Barin I, Knacke O. Thermochemical properties of inorganic substances. New York: Springer; 1973.Google Scholar
  23. 23.
    Beneš O, Konings RJM, Kuenzel C, Sierig M, Dockendorf A, Vlahovic L. The high-temperature heat capacity of the (Li, Na)F liquid solution. J Chem Thermodyn. 2009;41:899.CrossRefGoogle Scholar
  24. 24.
    Mukherjee S, Dash S, Mukerjee SK, Ramakumar KL. Thermodynamic investigations of oxyfluoride of thorium and uranium. J Nucl Mater. 2015;465:604.CrossRefGoogle Scholar

Copyright information

© Akadémiai Kiadó, Budapest, Hungary 2018

Authors and Affiliations

  • Sumanta Mukherjee
    • 1
    • 2
  • Rimpi Dawar
    • 1
    • 3
  • S. Phapale
    • 1
    • 3
  • S. Dash
    • 1
    • 2
  • R. Mishra
    • 1
    • 3
    Email author
  1. 1.Homi Bhabha National Institute (HBNI)Bhabha Atomic Research CentreTrombay, MumbaiIndia
  2. 2.Fuel Chemistry DivisionBhabha Atomic Research CentreTrombay, MumbaiIndia
  3. 3.Chemistry DivisionBhabha Atomic Research CentreTrombay, MumbaiIndia

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