Critical mixing exponents in molten salts

The pioneering results on the density and sound velocity of the NaCl-AgI molten mixture in two-phase region in the temperature range from the melting point to critical mixing point have been obtained. The properties of the coexisting equilibrium phases are shown to assimilate and as a result become almost indistinguishable in the critical mixing point (1064 K) as the temperature increase. The temperature dependences of densities and sound velocity differences in logarithmic coordinates are expressed in straight lines with the inclinations of 0.476 and 0.896, respectively. The critical exponents of density and sound velocity were found to be smaller than the analogous values for liquid alkali halides (0.52 and 1.02). This may be caused by a different degree of the covalent component in the energies of bond particles in these kinds of ionic melts. The result obtained is of great importance for  the nature of ionic systems segregation understanding.


  1. V.P. Stepanov, V.I. Minchenko. Ultrasonic velocity for an equimolar mixture of molten  AgI and NaCl in the biphasic region, J. Chem. Thermodynamics. 2013, V.59,  №4, Р.250-253.
  2. V.P. Stepanov, N.P. Kulik, K.G. Peshkina. Densities of a dissolving mixture of molten (AgI+NaCl), J. Chem. Thermodynamics, 2013, V.63, №8, Р. 84-87.

Authors: Stepanov V.P., DSc (Chemistry); Kulik  N.P., PhD (Chemistry);  Peshkina K.G., PhD-student.