Experimental determination and calculation of excess thermodynamic functions of molybdenum solid solutions in gamma-uranium

Abstract

The thermodynamic properties of the uranium-molybdenum system have been investigated in a temperature range from 1048 to 1173 K by means of the EMF method with a liquid electrolyte. The excess thermodynamic functions have been shown to change their signs depending on the concentration. The concentration dependencies of the excess entropy, enthalpy and free energy of mixing of the solid solution have been calculated for the above system at 1100 K on the basis of new physical concepts advanced for the solid solution. The calculated dependencies are in good (for entropy) and satisfactory (for the enthalpy and free energy of mixing) qualitative agreement with the experimental results. An interpretation is offered to explain the double change of sign of the excess entropy of mixing and the change of sign of the enthalpy of mixing as a function of the concentration.