Dynamics of simultaneous ordering and phase separation and effect of long-range Coulomb interactions.

The dynamics or simultaneous ordering and phase separation in the presence or a long-range Coulomb interaction is investigated by a computer simulation. It is shown that an intermediate nonstoichiometric ordered single phase appears as a transient phase during decomposition or a binary homogeneous disordered solid solution into an equilibrium two-phase mixture or ordered and disordered phases. Introduction or the long-range Coulomb interactions results in a mesoscale phase which consists or periodical arrays or ordered phase particles embedded in a disordered matrix