Thermodynamics of interstitial solid solutions communication 1. Energy of formation

Abstract

1. Starting from a few assumptions on the bond energies and atom positions in an interstitial solid solution, we have discussed the distribution of the interstitial atoms among two sublattices and the energy (heat) of formation of the solid solution. The heat of solution is, to a first approximation, a linear function of the composition, and the partial heats of solutions are constant; the partial heat of solution of the component with the larger atom radius depends mainly on the crystal structure. The (integral and differential) heat effects of formation of a solid solution with a single sublattice can be more accurately represented by power series. 2. At higher temperatures the distribution of the interstitial atoms among two sublattices markedly affects the thermodynamic functions of the solid solution. The effects on the energy (heat) of formation and the heat capacity were calculated on the assumption that the energy of transfer of interstitial atoms from one sublattice to the other is independent of the composition and the temperature.