The surface composition of a perfect (100) surface of a solid solution of monovalent ionic compounds AX and BX of NaCl structure was calculated using a monolayer model. The ions in the surface layer were assumed to possess dipole moments, and were allowed to relax from their perfect lattice positions. The surface composition was calculated by searching for the condition of lowest Gibbs free energy of the solid, which was predominantly determined by the coulombic and the repulsive interactions between ions. Thus, it is possible to express the surface composition as a function of the difference in the ionic radii of A and B, and in their repulsive parameters, for a given anion, temperature, and bulk composition. Results are presented for the solutions of NaClKCl, and AXBX where A and B were characterized by their electronic polarizabilities, their repulsive parameters, and the number of electrons of each ion.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Condensed Matter Physics
- Surfaces and Interfaces