Mixed-phase description of colossal magnetoresistive manganites

Abstract

In view of recent experiments, indicating the spatial coexistence of conducting and insulating regions in the ferromagnetic metallic phase of doped manganites, we propose a refined mixed-phase description. The model is based on the competition of a double-exchange driven metallic component and a polaronic insulating component, whose volume fractions and carrier concentrations are determined self-consistently by requiring equal pressure and chemical potential. The resulting phase diagram as well as the order of the phase transition are in very good agreement with measured data. In addition, modelling the resistivity of the mixed, percolative phase by a random resistor network, we obtain a pronounced negative magnetoresistance in the vicinity of the Curie temperature $T_C$.

arXiv comment7 pages, 6 figures

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Cited by in corpus (5)

• Orbital liquid in ferromagnetic manganites: The orbital Hubbard model for $e_g$ electrons
• Orbital polarons versus itinerant e_g electrons in doped manganites
• Doping dependence of spin and orbital correlations in layered manganites
• Percolative phase transition on ferromagnetic insulator manganites: uncorrelated to correlated polaron clusters
• Coherence of polaronic transport in layered metals