Phase-separation temperature in double-exchange manganites

Thermal fluctuation restores the segregated electronic phase to a homogeneous one at a certain point, the phase-separation (PS) temperature T-PS. In this paper, we theoretically investigate the dependence of the PS temperatures on doping and magnetic field in single- and two-orbital double exchange models. We find the Polaronic effect favors the PS, and predict an optimized separation temperature. Our results qualitatively interpret the novel electronic behaviors in doped double-exchange manganites.