Phase selection during calcium silicide formation for layered and powder growth

Phase selection during Ca silicide formation was discussed using the chemical potential and the effective heat of formation (ΔH′) models. The compositional analyses of Ca silicides were experimentally carried out in detail for both the layered and powder growth process. Based on the calculation, the Ca2Si phase has the largest negative ΔH′ and is the first phase to form in the Ca–Si system. In addition, the total energy consideration consisting of the formation energy of each phase and interfacial energy between two adjoining phases is proposed to explain the experimental results of phase selection in the Ca silicide formation.

Research highlights
► Phase selection of Ca silicide formation was discussed using the chemical potential.
► Composition of Ca silicides was experimentally examined.
► Total energy consideration is proposed to explain the experimental results.