ON THE EXISTENCE OF A TERNARY LIQUID MISCIBILITY GAP AND PHASE RELATIONS IN THE Fe-RICH CORNER OF THE La-Fe-Si SYSTEM

摘要

In this work we show that every La-Fe-Si sample with composition in the Fe-rich corner of the La-Fe-Si ternary phase diagram around the stoichiometry 1:13 shows a miscibility gap when solidified from the melt. This is the real reason why it is never possible (except in some particular cases) to obtain α-Fe free samples from La-Fe-Si system. We confirmed that the origin of this ternary gap is the binary miscibility gap in the La-Fe system (Massalski, 1990). We identified the phases coexisting in both liquids and determined their compositions, and determined the possible limits of the ternary miscibility gap.