Small polaron transport and colossal magnetoresistance in La2/3Ca1/3MnO3

Abstract

Phase diagram and spin-glass phenomena in electron-doped La1−xHfxMnO3 (0.05≤x≤0.3) manganite oxides J. Appl. Phys. 110, 113914 (2011) Rectifying characteristic of perovskite oxide La1.89Ce0.11CuO4/Ba0.5Sr0.5TiO3/La0.67Sr0.33MnO3 heterostructures J. Appl. Phys. 110, 103716 (2011) Strain modulated magnetization and colossal resistivity of epitaxial La2/3Ca1/3MnO3 film on BaTiO3 substrate Appl. Phys. Lett. 99, 092103 (2011) Magnetoresistance in epitaxial thin films of La0.85Ag0.15MnO3 produced by polymer assisted deposition Appl. Phys. Lett. 99, 083113 (2011) Additional information on J. Appl. Phys. Despite numerous attempts to explain the phenomenon of transport and magnetoresistance in manganites based on Jahn-Teller phonon coupling and double exchange mechanisms, satisfactory results could not be reached. The small polaron transport mechanism, based on the valence exchange arising from Madelung energy, is shown to account for the resistivity and magnetoresistance of the doped manganite La 2/3 Ca 1/3 MnO 3 in the ferromagnetic range. The transport equation for the correlated polaron based on the Holstein Hamiltonian shows the well known transition from the low temperature band to the localized polaron hopping conductivity at high temperature in agreement with experiment. The present attempt is to demonstrate that the complexity of the problem that involves the interplay between the spin and charge order on one hand and itinerant and localized behavior on the other for a simple ferromagnetic metal system of manganites is best described by the correlated small polaron model leaving the more complicated systems for future studies.

Synthesis and Characterization of Nanostructured Stannite Cu2ZnSnSe4 and Ag2ZnSnSe4 for Thermoelectric Applications

“…This type of behavior has been previously described by a two-component model whereby polaronic-type charge carriers are presumed to be composite polarons consisting of electrons surrounded by phonons and/or magnons . Eu chalcogenides, , colossal magnetoresistance compounds, and Ag-doped ZnO, whose carriers are primarily magnetic polarons, pentatellurides (e.g., ZrTe 5 and HfTe 5 ), whose carriers are lattice or dielectric polarons, and SrTiO 3 films, whose polarons are affected by electrons and vacancies, all display similar temperature dependent transport. In the case of Ag 2 ZnSnSe 4 , the electron–phonon interaction may cause self-trapping of electrons that forms a conducting band at low temperatures .…”

Enhancement of temperature coefficient of resistance (TCR) and magnetoresistance (MR) of La0.67–xRExCa0.33MnO3 (x = 0, 0.1; RE = Gd, Nd, Sm) system via rare-earth substitution

“…The enhancement in the resistivity ascribed to the distortion of MnO 6 octahedra and the enhancement of the magnetic domain scattering. As the resistivity is found to be less in Sm doped sample compare to Nd and Gd doped samples, it suggests that the magnetic domain scattering has more influence on overall resistivity enhancement [20,23]. We exploited different theoretical models related to electron conduction to unravel the electrical transport mechanism of the studied samples.…”

Peierls versus Holstein models for describing electron-phonon coupling in perovskites

“…Materials with perovskite structure ABO 3 are known to have a wide variety of extraordinary properties, ranging from unconventional high-temperature superconductivity in cuprates, [1][2][3][4] to an unusual metal-to-insulator transition in rare-earth nickelates, 5 to colossal magnetoresistance in manganites, 6,7 to multiferroic behaviour, 8 among others.…”