Related papers: Multi-scale Phase Modulations in Colossal Magnetor…
We report an experimental study of the time dependence of resistivity of a La$_{0.9}$Sr$_{0.1}$MnO$_{3}$ ultrathin film in order to elucidate the underlying mechanism for metal-insulator transition and colossal magnetoresistance CMR effect.…
We report the temperature and magnetic field dependence of transport properties in epitaxial films of the manganite La$_{1-x}$Ca$_{x}$MnO$_{3}$ in the overdoped region of the phase diagram for $x > 0.5$, where a charge--ordered (CO) and an…
We explain the observed specific heat anomaly (and hence entropy change) in the colossal magnetoresistive manganite Sm0.55Sr0.45MnO3, by introducing phase separation into the current carrier density collapse theory via the notion of the…
Materials with strong magnetoresistive responses are the backbone of spintronic technology, magnetic sensors, and hard drives. Among them, manganese oxides with a mixed valence and a cubic perovskite structure stand out due to their…
The effect of resistive switching in doped manganites being in the ferromagnetic state has been studied using resistive and magneto-optic methods. The visualization of magnetic structure of La0.75Sr0.25MnO3-x single crystals, and its…
Based on the combined model of the double exchange and the polaron, we have studied the small-to-large polaron crossover transition and explored its effects on the magnetic and transport properties in colossal magnetoresistance (CMR)…
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…
The "colossal magnetoresistive" (CMR) manganites are highly correlated systems with a strong coupling between spin, charge, orbital, and lattice degrees of freedom, which leads to complex phase diagrams and to the coexistence of various…
The exact nature of the low temperature electronic phase of the manganite materials family, and hence the origin of their colossal magnetoresistant (CMR) effect, is still under heavy debate. By combining new photoemission and tunneling…
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.,…
We study the possibility of nanoscale phase separation in manganites in the framework of the double exchange model. The homogeneous canted state of this model is proved to be unstable toward the formation of small ferromagnetic droplets…
The influence of quenched disorder on the competition between ordered states separated by a first-order transition is investigated. A phase diagram with features resembling quantum-critical behavior is observed, even using classical models.…
The properties of phase-separated systems, e.g. manganites, close to a I order phase transition between charge-ordered insulator and ferromagnetic metal, are usually described by the percolation picture. We argue that the correlated…
Recent experiments have shown that some colossal magnetoresistance (CMR) materials exhibit a percolation transition. The conductivity exponent varies substantially with or without an external magnetic field. This finding prompted us to…
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…
We present a detailed study of a model for strain-induced metal-insulator phase coexistence in perovskite manganites. Both nanoscale and mesoscale inhomogeneities are self-consistently described using atomic scale modes and their associated…
From Raman spectroscopy, magnetization, and thermal-expansion on the system La2/3(Ca1-xSrx)1/3MnO3, we have been able to provide a quantitative basis for the heterogeneous electronic model for manganites exhibiting colossal…
Phase separation and a tendency to form inhomogeneous structures seems to be a generic property of systems with strongly correlated electrons. After shortly summarising the existing theoretical results in this direction, I concentrate on…
Using a two-band double-exchange model with Jahn-Teller lattice distortions and super-exchange interactions, supplemented by quenched disorder, at electron density $n=0.65$, we explicitly demonstrate the coexistence of the $n$ = 1/2-type…
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.…