Related papers: The Phase Separation Scenario for Manganese Oxides
We address the issue of endemic electronic inhomogeneities in manganites using extensive simulations on a new model with Coulomb interactions amongst two electronic fluids, one localized (polaronic), the other extended (band-like), and…
A general quantitative measure of the tendency towards phase separation is introduced for systems exhibiting phase transitions or crossovers controlled by charge carrier concentration. This measure is devised for the situations when the…
We consider the nanoscale electronic phase separation in a wide class of different materials, mostly in strongly correlated electron systems. The phase separation turns out to be quite ubiquitous manifesting itself in different situations,…
The chemical influence in the phase separation phenomenon that occurs in perovskite manganites is discussed by means of ab initio calculations. Supercells have been used to simulate a phase separated state, that occurs at Ca concentrations…
The low temperature behavior of Pr$_{1-x}$Ca$_{x}$MnO$_{3}$ manganites are known to undergo a transition at $x\sim$0.3, from an insulating ferromagnetic state, at low Ca concentration, to an insulating antiferromagnetic state. Above the…
We present a systematic optical study for a bandwidth-controlled series of nearly half doped colossal magnetoresistive manganites RE$_{0.55}$AE$_{0.45}$MnO$_3$ (RE and AE being rare earth and alkaline earth ions, respectively) under the…
Pairing of oxygen holes into heavy bipolarons in the paramagnetic phase and their magnetic pair-breaking in the ferromagnetic phase [the so-called current-carrier density collapse (CCDC)] has accounted for the first-order ferromagnetic…
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…
One dimensional non-equilibrium systems with short-range interaction can undergo phase transitions from homogeneous states to phase separated states as interaction ($\epsilon$) among particles is increased. One of the model systems where…
We determine the ground-state phase-diagram of a Hubbard Hamiltonian with correlated hopping, which is asymmetric under particle-hole transform. By lowering the repulsive Coulomb interaction U at appropriate filling and interaction…
The phenomenon of colossal magnetoresistance in manganites is generally agreed to be a result of competition between crystal phases with different electronic, magnetic, and structural order; a competition which can be strong enough to cause…
The existence of a novel metal-insulator transition in the ferromagnetic state of models for undoped manganites is here discussed using numerical techniques applied to the $e_{\rm g}$-orbital degenerate Hubbard model tightly coupled with…
The colossal electroresistance in manganites is a concomitant of the electric field induced insulator-to-metal phase transition. A phenomenological phase transition model is proposed to study this electric field induced collapse of…
We present extensive large-scale dynamical simulations of phase-separated states in the double exchange model. These inhomogeneous electronic states that play a crucial role in the colossal magnetoresistance phenomenon are composed of…
Extensive experimental results are presented on the multi-scale phase modulation phenomena observed in colossal magnetoresistance manganites. Two key types of phase inhomogeneities directly relevant to the colossal magnetoresistance (CMR)…
A short introduction to the complex phenomena encountered in transition metal oxides with either charge or orbital or joint charge-and-orbital order, usually accompanied by magnetic order, is presented. It is argued that all the types of…
We study the existence of incommensurate phases in the phase diagram of the two orbital double exchange model coupled with Jahn-Teller phonons and with superexchange interactions. In agreement with experimental results, we find that undoped…
Phase-coexistence in the manganese-oxide compounds or manganites with colossal magneto-resistance (CMR) has been generally considered to be an inhomogeneous ground state. An alternative explanation of phase-coexistence as the manifestation…
The effect of giant dielectric permittivity due to phase separation accompanied by charged inhomogeneities in low-doped manganites is discussed. The effect appears in the vicinity of the second-order magnetic phase transition and is caused…
We study a 3-dimensional Ising model in which the tendency to order due to short-range ferromagnetic interactions is frustrated by competing long-range (Coulombic) interactions. Complete ferromagnetic ordering is impossible for any nonzero…