Phase equilibrium in two orbital model under magnetic field

The phase equilibrium in manganites under magnetic field is studied using a two orbital model, based on the equivalent chemical potential principle for the competitive phases. We focus on the magnetic field induced melting process of CE phase in half-doped manganites. It is predicted that the homogenous CE phase begins to decompose into coexisting ferromagnetic phase and CE phase once the magnetic field exceeds the threshold field. In a more quantitative way, the volume fractions of the two competitive phases in the phase separation regime are evaluated.