相关论文: Dynamics of Phase Separated States in the Double E…
This work examines the magnetic order and spin dynamics of a double-exchange model with competing ferromagnetic and antiferromagnetic Heisenberg interactions between the local moments. The Heisenberg interactions are periodically arranged…
The effect of electron doping on the structural, transport, and magnetic properties of Mn (IV) - rich Ca1-xYxMnO3 (x < 0.2) samples have been investigated using neutron diffraction, neutron depolarization, magnetization and resistivity…
The phase diagram of the double exchange model is studied in the large-S limit at zero temperature in two and three dimensions. We find that the spiral state has lower energy than the canted antiferromagnetic state in the region between the…
The double exchange (DE) model is systematically applied for studying the coupling between ferroelectric (FE) and magnetic orders in several prototypical types of multiferroic manganites. The model was constructed for the magnetically…
The microstructure and mechanical behavior of dual-phase steels are highly sensitive to the variation of the process (heat treatments). Online control by magnetic method is relevant. A measurement under applied stress must be considered.…
We introduce a new coarse grain model capable of describing the phase behavior of two dimensional ferromagnetic systems with competing exchange and dipolar interactions, as well as an external magnetic field. An improved expression for the…
In this review, the present status of theories for manganites is discussed. The complex phase diagrams of these materials, with a variety of spin-charge-orbital ordering tendencies, is addressed using mean-field and Monte Carlo simulation…
We study the phase diagram of the double exchange model, with antiferromagnetic interactions, in a cubic lattice both at zero and at finite temperature. There is a rich variety of magnetic phases, combined with regions where phase…
A recent vast experimental and theoretical effort in manganites has shown that the colossal magnetoresistance effect can be understood based on the competition of charge-ordered and ferromagnetic phases. The general aspects of the…
A "minimal model" of the Kondo-lattice type is used to describe a competition between the localization and metallicity in doped manganites and related magnetic oxides with Jahn-Teller ions. It is shown that the number of itinerant charge…
The two-orbital model for manganites with both non-cooperative and cooperative Jahn-Teller phonons is studied at hole density x=0.5 using Monte Carlo techniques. The phase diagram is obtained varying the electron-phonon coupling and the…
Cooperation and competition between the antiferromagnetic, d-wave superconducting and Mott-insulating states are explored for the two-dimensional Hubbard model including nearest and next-nearest-neighbor hoppings at zero temperature. Using…
We study a classical double exchange magnet with direct antiferromagnetic superexchange coupling, J, between the localized spins. It is shown that the de-stabilization of the ferromagnetic ground state with increasing J leads to phase…
Starting from the assumption that ferromagnetically correlated regions exist in manganites even in the absence of long-range magnetic order, we construct a model of charge transfer due to the spin-dependent tunnelling of charge carriers…
The physics of ferromagnetic doped manganites, such as \chem{La_{1-x}Ca_xMnO_3} with $x\approx0.2$--0.4, is reviewed. The concept of double exchange is discussed within the general framework of itinerant electron magnetism. The new feature…
The phase diagram of the ferromagnetic Kondo model for manganites is investigated using computational techniques. In clusters of dimensions 1 and 2, Monte Carlo simulations in the limit where the localized spins are classical show a rich…
The double exchange model describing interactions of itinerant electrons with localized spins is usually used to explain ferromagnetism in metals. We show that for a variety of crystal lattices of different dimensionalities and for a wide…
We discuss the phase diagram of the two-orbital model of half-doped manganites by calculating self-consistently the Jahn-Teller (JT) distortion patterns, charge, orbital and magnetic order at zero temperature. We analyse the instabilities…
Giant oxygen isotope effects observed in colossal magnetoresistance manganites are investigated by employing the combined model of the double exchange and interacting lattice polaron mechanism. We have shown that the isotope effects on $…
We study, using simulations the dynamical properties of complex ferromagnetic granular materials. The system of grains is modeled by a disordered two-dimensional lattice in which the grains are embedded, while the magnitude and direction of…