Related papers: Phase Separation in Models for Manganites: Theoret…
We report a study of oxygen isotope effects on low temperature specific heat, magnetization, and resistivity of La$_{1-x}$Ca$_{x}$MnO$_{3}$ and (La$_{1-y}$Pr$_{y})_{0.67}$Ca$_{0.33}$MnO$_{3}$. For the metallic compositions of…
We present a single-orbital double-exchange model, coupled with cooperative phonons (the so called breathing-modes of the oxygen octahedra in manganites). The model is studied with Monte Carlo simulations. For a finite range of doping and…
Magnetization, magnetoresistance, and magnetodielectric measurements have been carried out on the half doped charge ordered manganite, Pr_0.5Ca_0.5MnO_3. The low temperature state is found to be strongly dependent on the oxygen…
Nominally pure undoped parent manganite LaMnO_3 exhibits a puzzling behavior inconsistent with a simple picture of an A-type antiferromagnetic insulator (A-AFI) with a cooperative Jahn-Teller ordering. We do assign its anomalous properties…
We have derived the interaction between Jahn-Teller centers due to optical and acoustic phonons. Without Coulomb repulsion the model leads to a global phase separation at low temperature. At long distances Coulomb repulsion always dominates…
The persistent proximity of insulating and metallic phases, a puzzling characterestic of manganites, is argued to arise from the self organization of the twofold degenerate e_g orbitals of Mn into localized Jahn-Teller(JT) polaronic levels…
In this report, we study in detail the competitor to the FM metallic state at electronic density $x=1/4$ in the CMR regime using the two-orbital double-exchange model with Jahn-Teller lattice distortions on two-dimensional clusters,…
We present a linear spin and orbital wave theory to account for the spin and orbital orderings observed experimentally in undoped manganite. It is found that the anisotropy of the magnetic structure is closely related to the orbital…
We propose a dielectrophoresis model for phase-separated manganites. Without increase of the fraction of metallic phase, an insulator-metal transition occurs when a uniform electric field applied across the system exceeds a threshold value.…
Variation of magnetocaloric (MC) effects has been systematically investigated for colossal magnetoresistive (CMR) manganites R0.6Sr0.4MnO3 (R=La-Gd). As the one-electron bandwidth is reduced, the temperature profile of MC effect, i.e.,…
The physics of manganites appears to be dominated by phase competition among ferromagnetic metallic and charge-ordered antiferromagnetic insulating states. Previous investigations (Burgy {\it et al.}, Phys. Rev. Lett. {\bf 87}, 277202…
The 2D ferromagnetic Kondo model with classical corespins is studied for a hole doping up to x = 0.125 via unbiased Monte Carlo (MC) simulations. A canonical algorithm for finite temperatures is developed. We show that with realistic…
The metal-insulator transition in manganites is strongly influenced by the concentration of holes present in the system. Based upon an orbitally degenerate Mott-Hubbard model we analyze two possible localization scenarios to account for…
In complex electronic materials, coupling between electrons and the atomic lattice gives rise to remarkable phenomena, including colossal magnetoresistance and metal-insulator transitions. Charge-ordered phases are a prototypical…
Colossal enhancement of magnetoresistance has been achieved over a broad temperature range which extends upto the room temperature, in ferromagnetic metal-charge ordered insulator manganite multi-layers. The artificially created phase…
There have been recent reports of charge ordering around $x=0.5$ in the bilayer manganites. At $x=0.5$, there appears to be a coexistence region of layered A-type antiferromagnetc and charge order. There are also reports of orbital order in…
Quantum phase transitions (QPTs) have been studied extensively in correlated electron systems. Characterization of magnetism at QPTs has, however, been limited by the volume-integrated feature of neutron and magnetization measurements and…
1% $^{119}$Sn-doped La$_{0.5}$Ca$_{0.5}$MnO$_3$ was studied by M\"ossbauer spectroscopy, magnetic moment and resistivity measurements. The M\"ossbauer spectra below the charge-ordering temperature are explained with ferromagnetic (FM),…
Spatially resolved tunneling spectroscopic studies of colossal magnetoresistive (CMR) manganite $\rm La_{0.7}Ca_{0.3}MnO_3$ (LCMO) epitaxial films on $\rm (LaAlO_3)_{0.3}(Sr_2AlTaO_6)_{0.7}$ substrate are investigated as functions of…
Hole doped transition metal oxides are famous due to their extraordinary charge transport properties, such as high temperature superconductivity (cuprates) and colossal magnetoresistance (manganites). Astonishing, the mother system of these…