Double-exchange model: phase separation versus canted spins

摘要: We study the competition between different possible ground states of double-exchange model with strong ferromagnetic exchange interaction itinerant electrons and local spins. Both for classical quantum treatment spins homogeneous canted state is shown to be unstable against a phase separation. The conditions separation into mixture antiferromagnetic ferromagnetic/canted are given. also discuss another realization phase-separated state: polarons embedded an surrounding. general picture percolated state, which emerges from these considerations, discussed compared results recent experiments on doped manganaties.