Results 171 to 180 of about 15,658 (215)
Some of the next articles are maybe not open access.
physica status solidi (b), 2003
AbstractThe interplay of the electron–phonon interaction and of the double and super‐exchange magnetic effects in the La1–xCaxMnO3 perovskites with 0 < x < 0.5 is studied. It is shown that treating the electron–phonon interaction in a fully quantum manner in the intermediate electron–phonon coupling regime a charge density instability occurs near
IADONISI, GIUSEPPE +5 more
openaire +2 more sources
AbstractThe interplay of the electron–phonon interaction and of the double and super‐exchange magnetic effects in the La1–xCaxMnO3 perovskites with 0 < x < 0.5 is studied. It is shown that treating the electron–phonon interaction in a fully quantum manner in the intermediate electron–phonon coupling regime a charge density instability occurs near
IADONISI, GIUSEPPE +5 more
openaire +2 more sources
International Journal of Modern Physics B, 2000
Topological aspects of the stripe structure in manganese oxides are discussed in terms of the "winding number" w associated with the Berry-phase conncection for e g orbitals acquired by the parallel transport through the periodic array of Jahn-Teller centers.
Takashi Hotta +3 more
openaire +1 more source
Topological aspects of the stripe structure in manganese oxides are discussed in terms of the "winding number" w associated with the Berry-phase conncection for e g orbitals acquired by the parallel transport through the periodic array of Jahn-Teller centers.
Takashi Hotta +3 more
openaire +1 more source
Photoconductivity in Manganites
Journal of Superconductivity, 2000We report two types of photoconductivity effects observed by illumination of oxygen deficient manganites thin films with UV or visible light. One is the persistent photoconductivity effect observed at low temperature (T < 30 K) when the thin film is in the metallic state.
A. Gilabert +6 more
openaire +1 more source
Piezoresistivity in Films of Nanocrystalline Manganites
Journal of Nanoscience and Nanotechnology, 2007Rare earth manganites having perovskite structure are susceptible to lattice strain. So far most investigations have been done with hydrostatic pressure or biaxial strain. We have observed that hole doped rare-earth manganites, which are known to display colossal magnetoresistance (CMR) also show change in its resistance under the influence of uniaxial
Sarkar, Jayanta, Raychaudhuri, AK
openaire +2 more sources
Magnetic Filaments in Resistive Manganites
Physical Review Letters, 2004The magnetic phase separation in single crystals of the Pr0.67Ca0.33MnO3 manganites is studied using polarized small angle neutron scattering. The measured spectra give a fractal dimension consistent with a configuration in ferromagnetic filaments of nanometric diameter.
M, Viret +5 more
openaire +2 more sources
SPIN AND ORBITAL PHYSICS IN MANGANITES
International Journal of Modern Physics B, 2001The spin and orbital physics in perovskite manganites is briefly reviewed. Perovskite manganites are well known as the materials exhibiting colossal magnetoresistance (CMR), whose mechanism is based on the double exchange (DE) interaction, in which the electron hopping is connected with the spin configurations of the manganite ions.
Wang, ZD, Gu, RY
openaire +2 more sources
2003
In the previous chapter, an electronic model was derived for the case of several nearly degenerate orbitals in a given ion. The resulting model, which included on site Coulombic interactions (4.17, 4.18), was found to be very general, and its applicability goes beyond the manganites into ruthenates, nickelates, and other multiorbital compounds.
openaire +1 more source
In the previous chapter, an electronic model was derived for the case of several nearly degenerate orbitals in a given ion. The resulting model, which included on site Coulombic interactions (4.17, 4.18), was found to be very general, and its applicability goes beyond the manganites into ruthenates, nickelates, and other multiorbital compounds.
openaire +1 more source
Magnetic and orbital ordering in the manganites
Physica B: Condensed Matter, 1999We present an analysis of superexchange and double exchange interactions in colossal magnetoresistance manganites. The superexchange explains the A-type antiferromagnetic and orbital ordering observed in LaMnO3, and the doping dependence of the anisotropic exchange constants J (a,b) and J c in the polaronic phase for doping by x ≤ 0.1 holes.
Feiner, L., Oleś, A.
openaire +3 more sources
Orbitons in ferromagnetic insulating manganites
Physica B: Condensed Matter, 1999Abstract Starting from the classical ground state with orbital order, we investigate the orbital excitations (orbitons) and quantum corrections in the model for insulating ferromagnetic LaMnO 3 using linear spin-wave theory. It is found that the effective dimensionality of the model is reduced, and the quantum corrections are smaller than in the ...
van den Brink, J. +3 more
openaire +2 more sources
2002
Series Preface. Preface. Thermodynamics of the Double Exchange System N. Furukawa. Phase Separation in Models for Manganites: Theoretical Aspects and Comparison with Experiments E. Dagotto et al. Two Ferromagnetic States in Magnetoresistive Manganites: First Order Transition Driven by Orbitals S. Maekawa et al.
openaire +1 more source
Series Preface. Preface. Thermodynamics of the Double Exchange System N. Furukawa. Phase Separation in Models for Manganites: Theoretical Aspects and Comparison with Experiments E. Dagotto et al. Two Ferromagnetic States in Magnetoresistive Manganites: First Order Transition Driven by Orbitals S. Maekawa et al.
openaire +1 more source