相关论文: Microscopic modelling of doped manganites

A macroscopic phase separation, in which ferromagnetic clusters are observed in an insulating matrix, is sometimes observed, and believed to be essential to the colossal magnetoresistive (CMR) properties of manganese oxides. The application…

Correlation-induced spin-charge and spin-orbital coupling effects on spin dynamics in ferromagnetic manganites are calculated with realistic parameters in order to provide a quantitative comparison with experimental results for spin…

The spin-charge-orbital complex structures of manganites are studied using topological concepts. The key quantity is the "winding number" w associated with the Berry-phase connection of an e_g electron parallel-transported through…

The magnetization in a magnetic microdot made from soft magnetic materials can have a vortex-like ground state structure resulting from competition between the exchange and dipolar interactions. Normal mode magnon frequencies for such dots…

We study theoretically the phase diagram of perovskite manganites taking into account the double degeneracy of the $e_g$ orbitals in a $Mn^{3+}$ ion. A rich phase diagram is obtained in the mean field theory at zero temperature as functions…

In this paper we report the results of the synthesis and structural, transport and magnetic characterization of pure La0.5Sr1.5MnO4 (LSMO) and 5% doped samples, i.e. La0.5Sr1.5Mn0.95B0.05O4, where B = Ru, Co and Ni. It is shown that even a…

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…

The spin-fermion model was previously successful to describe the complex phase diagrams of colossal magnetoresistive manganites and iron-based superconductors. In recent years, two-dimensional magnets have rapidly raised up as a new…

Electrical and magnetic properties of four series of manganates LnxCa1-xMnO3 (Ln=La, Nd, Gd and Y) have been studied in the electron doped regime (x=0.02-0.25) in order to investigate the various inter-dependent phenomena such as…

The interaction of a single manganese impurity with silicon is analyzed in a combined experimental and theoretical study of the electronic, magnetic, and structural properties of manganese-doped silicon clusters. The structural transition…

In recent decades, novel magnetism of $d$- and $f$-electron compounds has been discussed very intensively both in experimental and theoretical research fields of condensed matter physics. It has been recognized that those material groups…

We use neutron scattering to study the lattice and magnetic structure of the layered half-doped manganite Pr$_{0.5}$Ca$_{1.5}$MnO$_4$. On cooling from high temperature, the system first becomes charge- and orbital- ordered (CO/OO) near…

A microscopic understanding of magnetoelectricity, i.e. the coupling between magnetic (electric) properties and external electric (magnetic) fields, is a crucial milestone for future generations of electrically-controlled spintronic…

We formulated a technique which combines the first-principles, micromagnetic and microstructural calculations and allows us to study the nature of hysteretic phenomena in hard magnets. Two distinct sources of coercivity in polytwinned CoPt…

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 have recently argued that manganites do not possess stripes of charge order, implying that the electron-lattice coupling is weak [Phys Rev Lett \textbf{94} (2005) 097202]. Here we independently argue the same conclusion based on…

We present a small-but-sizeable magnetic polaron picture where transport at high temperatures is activated while at low temperatures it is band-like. We show that both double exchange and finite bandwidth effects are important to understand…

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 competition among different phases in perovskite manganites is pronounced since their energies are very close under the interplay of charge, spin, orbital and lattice degrees of freedom. To reveal the roles of underlying interactions,…

The resistivity $\rho_{dc}$ of manganites is studied using a random-resistor-network, based on phase-separation between metallic and insulating domains. When percolation occurs, both as chemical composition and temperature vary, results in…