The phase stability of e-Fe alloys

The hexagonal close packed e-phase of Fe, which is of particular interest in the study of shape memory effects in some Fe-based alloys, can be stabilized in pure Fe under a pressure of about 11 GPa. Also, Fe will be in the e-phase in the absence of ferromagnetic correlations in the a-phase. Therefore, an alternative to applying pressure to stabilize the e-phase is to destroy the long range ferromagnetic ordering in <x-Fe by alloying appropriate elements. In this study we discuss the relationship of the magnetic properties and the stability of the €-phase in Fe and Fe-rich alloys with the aid of thermodynamical considerations and total energy calculations.