Prediction of Silicide First Phase and Phase Sequence from Heats of Formation

Abstract

ABSTRACTAn effective heat of formation (δH') is formulated, enabling δH' to be calculated as a function of the concentration of metal and silicon available for interaction to form a silicide. A rule for first phase formation is proposed according to which, “The first silicide compound to form during metal-silicon interaction is the congruent phase with the most negative effective heat of formation at the concentration of the lowest eutectic temperature of the binary system.” The effective heat of formation concept is also extended to predict subsequent phase sequence.