Electric Conductivity of Delaminated AgI + NaCl Mixture

The liquid–liquid phase equilibrium for the melted AgI + NaCl mixture was studied by the impedance method over a wide range of temperatures along the saturation line to correlate the charge transfer in two-phase ion systems with the nature of the chemical bond. The temperature dependences of the specific electric conductivity κ of the coexisting phases have opposite signs because of the superposition of the temperature and concentration factors that act in the same or opposite directions. The difference between the κ values for the equilibrium phases decreases with increasing temperature, becoming zero at 1064 K. Near the critical mixing point, the temperature dependence of the difference between the conductivities of the coexisting phases is described by the exponential equation with a critical exponent of 0.91, which is 8% smaller than that found for alkali metal halides with primarily Coulomb forces acting between the ions.