Stability, thermodynamic and mechanical properties of the compounds in the Ag-Sn-O system

The stability and mechanical properties of the compounds in the Ag/SnO₂ composite by reaction synthesis are investigated with the advantage of density functional theory. Cohesive energy and formation enthalpy show that the calculated compounds are stable and the stability is aligned as Ag₂O<SnO∼Ag₂SnO₃<Ag₆O₂∼SnO₂. Similar results are also obtained by the Milliken population analysis. The crystal structures of Ag₈Sn₄O₁₂ (supercell of Ag₂SnO₃) could be produced by the reaction between 2×Ag₆O₂ and 4×SnO₂; the formation energy is about -164.95 kJ/mol. The thermodynamical data of these compounds are calculated using Debye's quasi-harmonic approximation, such as heat capacity and Gibbs free energy. Bulk modulus, Young's modulus and shearing modulus values are obtained by the Voigt-Reuss-Hill method.