  The temperature dependent stability of the magnetic phases of FeRh were
investigated by means of total energy calculations with magnetic disorder
treated within the uncompensated disordered local moment (uDLM) approach. In
addition, Monte Carlo simulations based on the extended Heisenberg model have
been performed, using exchange coupling parameters obtained rom first
principles. The crucial role and interplay of two factors in the metamagnetic
transition in FeRh has been revealed, namely the dependence of the Fe-Fe
exchange coupling parameters on the temperature-governed degree of magnetic
disorder in the system and the stabilizing nature of the induced magnetic
moment on Rh-sites. An important observation is the temperature dependence of
these two competing factors.
