Analysis of the singular features and internal consistency of the thermodynamic properties of binary alkali-metal coolants, based on the correlation function of concentration fluctuations

The stability of a binary liquid-metal alloy as a homogeneous single-phase system is analyzed; a criterion is validated for the estimation of the internal consistency of the thermodynamic and structural properties, as well as of the reliability of the experimental data on the Gibbs energy of solution formation $\Delta G$ and of the methods for approximating these data, and of the theoretical models reproducing the $\Delta G$ behavior in systems of alkali metals. The analysis is based on the construction of the correlation function of concentration fluctuations $S_{cc}(0)=f(T,x_i)$ using the experimental data obtained in the range of temperatures $400\le T\le1200$ K and concentrations $0\le x_i\le1$ for $\mathrm{Cs}$–$\mathrm{Na}$, $\mathrm{K}$–$\mathrm{Na}$, and $\mathrm{Cs}$–$\mathrm{K}$ systems.