The surprising role of magnetism on the phase stability of Fe (Ferro)

We discuss the phase stability of the important element Fe in terms of the contributions to stability from the various forms of magnetism that exist in Fe. We point out that the ferromagnetic Fe is not cubic and that it is reasonable to return the beta phase of Fe to the phase diagrams based on Fe to designate paramagnetic BCC form of iron. We give a working definition of a phase, which includes the term “order parameter” following the insights of Landau.