Antiferromagnetism and phase separation in electronic models for doped transition-metal oxides

Abstract

We investigate the ground state properties of electronic models for doped manganites and nickelates. An effective t - J like Hamiltonian is derived from the case of strong Hund coupling between the conduction electrons and localized spins by means of the projection technique. An attractive interaction for conduction electrons and an anti-ferromagnetic coupling of the localized spin are obtained. A large ratio of the attraction to effective electron hopping, which is modulated by the spin background, will lead to the phase separation. The anti-ferromagnetic phase and the phase separation appear in the case of either high or low density of electrons. The possible relevance of the phase separation to the charge stripe phase in the manganites and nickelates is discussed.

12 pages, ReVTEX, 3 figures. To appear in Phys. Rev. B (RC), (01Oct., 1998)

References in corpus (2)

• Static and Dynamical Properties of the Ferromagnetic Kondo Model with Direct Antiferromagnetic Coupling Between the localized $t_{2g}$ Electrons
• Charge and Spin Dynamics of an Ordered Stripe Phase in La_(1 2/3)Sr_(1/3)NiO_4 by Raman Spectroscopy

Cited by in corpus (17)

• Colossal Magnetoresistant Materials: The Key Role of Phase Separation
• Phase Separation Induced by Orbital Degrees of Freedom in Models for Manganites with Jahn-Teller Phonons
• Inhomogeneous magnetism in La-doped CaMnO3. (I) Nanometric-scale spin clusters and long-range spin canting
• Orbital Degree of Freedom and Phase Separation in Ferromagnetic Manganites at Finite Temperatures
• Influence of Nearest-Neighbor Coulomb Interactions on the Phase Diagram of the Ferromagnetic Kondo Model
• Charge ordering and phase separation in the infinite dimensional extended Hubbard model
• Unified theory of phase separation and charge ordering in doped manganite perovskites
• Theory for high spin systems with orbital degeneracy
• Landau Theory of the Phase Transitions in Half Doped Manganites: Interplay of Magnetic, Charge and Structural Orders
• Phase diagram of an extended Kondo lattice model for manganites: the Schwinger-boson mean-field approach
• Symmetry Origin of the Phase Transitions and Phase Separation in Manganites at Low Doping
• An effective Hamiltonian for an extended Kondo lattice model and a possible origin of charge ordering in half-doped manganites
• Spiral phase and phase separation of the double exchange model in the large-S limit
• Dynamical Mean-Field Solution for a Model of Metal-Insulator Transitions in Moderately Doped Manganites
• Spin current in the Kondo lattice model
• Ferromagnetic ground state of an orbital degenerate electronic model for transition-metal oxides: exact solution and physical mechanism
• Joint effect of lattice interaction and potential fluctuation in colossal magnetoresistive manganites