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Showing 1 to 20 of 29 for “"Manganites"”.
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Phase Coexistence in Manganites
The doped perovskite manganite La1-xCaxMnO3 (0<x<1) has been extensively studied due to the interactions between the electronic, magnetic and crystal lattices, and the wide range of phases that can coexist. The region of greatest interest in the bulk material is around x~0.5, where there is often …
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Ferromagnetic manganites: spin-polarized conduction and competing interactions
Electronic properties of solids are vitally important for modern technology, one may think of microelectronics, magnetic data storage, communication technologies and others. Sometimes, it seems possible to postpone the step of fundamental understanding when starting the application of a new …
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Probing spin, charge and lattice coupling in manganites
Complex oxides such as the manganites exhibit an intimate coupling of the electron spin, charge and lattice degrees of freedom. The characteristic feature of these materials is the existence of a ground state topology with many closely lying minima. The system can be switched from one minimum to …
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Magnetic structure in manganites as probed by magnetic force microscopy
This dissertation describes the use of magnetic force microscopy to directly measure the magnetic structure of a sample on a microscopic level. Our magnetic force microscope has been operated at temperatures ranging from 293 to 4.3 K and fields ranging from 0 to 3 T, providing a method for imaging …
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Structural, electro-magnetic and electrical analysis in monovalent doped Nd0.75Na0.25-xKxMnO3 manganites
… using solid state reaction method. K doped manganites have been investigated to study its effect on crystalline phase and surface morphology as well as electrical transport and magnetic properties. However most of study show inconsistent result regarding to the electrical transport and …
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Influence of ag-doped on magnetic and electrical transport properties in Pr0.75Na0.25MnO3 manganites
The manganites compound in which composed of the manganese oxide are attract considerable attention among researcher due to their electrical and magnetic properties at lower temperature. However, most of the doping does not totally induce the ferromagnetic-metallic (FMM) state probably due to …
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Redox cycles with doped calcium manganites for high-temperature thermochemical energy storage in concentrating solar power
Redox cycles with reducible perovskite oxides of the form ABO$_3$ can provide thermochemical energy storage (TCES) with higher energy density and storage temperatures than molten-salt systems for large-scale energy storage in concentrating solar power (CSP). Perovskites from earth abundant cations …
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Study on structure, surface morphology, electrical and magnetic properties in monovalent doped Pr0.75Na0.25Mn1-xCrxO3 AND Nd0.75Na0.25Mn1-yCryO3 of magnetic ceramics
In perovskite manganites, Mn site substitution of Cr ion have attract great interest to suppress CO and induce phase transition. However most of study show inconsistent result regarding to the crystalline phase, surface morphology and magnetic properties as well as electrical properties study. …
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Photoinduced phase transitions and irreversible dynamics studied with single-shot spectroscopy
… photoinduced phase transitions in semimetals and manganites. The dual-echelon single-shot instrument was developed, and noise sources, experimental artifacts, and the fundamental limits of the single-shot technique were explored. In this thesis, advances in the single-shot technique that allow for …
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Structural, transport and magnetic studies of perovskite Bi1-x Cax Mn O3
… to a group of simple perovskites called the manganites which are of technological importance for magnetic device applications as read-head sensors. The Bi_{1-x}Ca_xMnO_3 system is known to exhibit charge ordering (and high sensitivity to magnetic fields) for a much broader range of x than the …
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Theoretical studies of structural and electronic properties in transition metal oxides
… Jahn-Teller distortions in undoped perovskite manganites, and symmetry-mode-based classical and quantum mechanical formalism of lattice dynamics. The formula based on tight-binding approach for the calculation of K-edge resonant inelastic x-ray scattering (RIXS) spectrum for transition metal …
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Theory of lattice effects on magnetic interactions in solids
… on the magnetic properties of nickelates and manganites. These two families of materials have great potential in industrial applications in the fields of magnetic (superdense hard-drives, fast memory) and charge storage (batteries). The introduction and methods sections present the main ideas …
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Ladungs- und Orbitalordnungsphänomene in Übergangsmetalloxidverbindungen unter hydrostatischem Druck
… metal oxide compounds, i.e. doped cuprates and manganites, which belong to the class of strongly correlated electron systems. The 1/8-doped cuprate La_{2-x}Ba_{x}CuO_{4} reveals an ordered state at low temperatures. Inside the CuO_{2} planes a combined order of charge stripes and …
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Critical behavior and transport properties of lanthanum manganite
… well before the entire system orders. The manganites' magnetic heat capacity peak has been observed to shift upward in temperature with applied magnetic field unlike that of ordinary ferromagnets. In the double exchange picture proposed by Zener, magnetism is closely linked to the nature of …
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Electrical and structural properties of compositions in the systems Y₁₋ₓCaₓMnO₃ and La₁₋ₓCaₓMnO₃
… to the oxygen activity-dependent region in manganites. The disproportionation model was successful in explaining the experimentally observed dependence of oxygen stoichiometry, electrical conductivity, and Seebeck coefficient upon ambient oxygen activity"--Abstract, page iii.</p>
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Charged ferroelectric domain walls: the next generation in 2D functional materials
… bulk ferroelectrics. In the rare-earth hexagonal manganites, YbMnO3 and ErMnO3, I worked on the development of local potential mapping techniques in AFM such as Kelvin probe force microscopy (KPFM) to spatially map the Hall potential on the nanoscale. This allowed the behaviour of the wall to be …
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Synchrotron radiation-based characterization of GaN- based MQW structures and strongly correlated materials
… to the fields of gallium nitrides, multiferroic manganites, and self-assembled nano-domain oxide films. These material systems were chosen due to their unusual properties and potential device applications, which have made them very attractive to the scientific community. Synchrotron-based High …
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High pressure effects on electron transport and structure of colossal magnetoresistive materials
… of several typical colossal magnetoresistive manganites, La_{0.60}Y_{0.07}Ca_{0.33}MnO_3, Pr_{1-x}Ca_xMn0_3 (X = 0.25, 0.30, 0.35), Nd_{1-x}Sr_xMnO_3 (x = 0.45, 0.50), were explored through high pressure resistivity and structure measurements. It was shown that pressure up to ~7 GPa induces …
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Magneto-transport properties of manganite/secondary phase inhomogeneous systems
… granularity effect on related properties in manganites, by introducing secondary phases into a ferromagnetic manganite forming an inhomogeneous manganite/secondary phase system. TiO2 insulator was introduced as a secondary phase into the ferromagnetic La0.7Ba0.3MnO3 (LBMO) manganite with …
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