Novel correlation of Schottky constants with lattice energies for II–VI and I–VII compounds

Correlations of computed Schottky constants (View the MathML sourceKS=[V″Zn][VS··]) with structural and thermodynamic properties showed linear dependences of log K S on the lattice energies for the Zn-, Cd-, Hg-, Mg-, and Sr-chalcogenides and for the Na- and K-halides. These findings suggest a basic relation between the Schottky constants and the lattice energies for these families of compounds from different parts of the Periodic Table, namely, View the MathML sourceΔHT,Lo=−(2.303nRT log KS)+2.303nRmb+2.303nRTib. View the MathML sourceΔHT,Lo is the experimental (Born–Haber) lattice energy (enthalpy), n is a constant approximately equal to the formal valence (charge) of the material, m b and i b are the slope and intercept, respectively, of the intercept b (of the log K S versus View the MathML sourceΔHLo linear relation) versus the reciprocal temperature. The results of this work also provide an empirical correlation between the Gibbs free energy of vacancy formation and the lattice energy.