Modeling of Thermodynamic Properties and Phase Equilibria of the Si-P System

A Calphad assessment of the Si-P system is performed based on critical review of all available original experimental thermodynamic and phase equilibrium data. It is demonstrated that a simple disordered substitutional solution model is sufficient for the liquid phase and that previous assumptions of short-range ordering in the Si-P liquid phase may not be justified. Alternative model descriptions for the Gibbs energy of the (Si) solid solution phase were developed to reveal the consequences in describing the largely scattering solid solubility data of P in (Si). Two alternative sets of consistently calculated phase boundaries of the (Si) phase are shown. It is impossible to reconcile the only experimental (Si) solidus data with the solvus data from the same work.