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Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 91 for “"Ferromagnet"”.
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Ferromagnet-insulator-ferromagnet tunneling with one half-metallic electrode
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1996.
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Growth and characterisation of Niobium/Gadolinium superconductor-ferromagnet nanocomposites
Superconductivity and ferromagnetism are two antagonistic physical phenomena which their coexistence in a uniform material can be resolved only under extraordinary conditions. The reason for that is the phonon-mediated attraction energy between electrons which results in the formation of the …
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Scanning Tunneling Microscopy and Spectroscopy Measurements of Superconductor/Ferromagnet Hybrids
… of magnetically coupled superconductor/ferromagnet hybrid structures using low-temperature scanning tunneling microscopy and spectroscopy (LT-STM/STS) under ultra-high vacuum conditions. There are a number of novel effects that can occur due to the non-homogenous magnetic field from the …
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Investigations of Crossed Andreev Reflection in Hybrid Superconductor-Ferromagnet Structures
… devices where a superconductor is coupled to two ferromagnetic wires placed at a distance less than the superconducting coherence length. This thesis searches for signatures of this process, called crossed Andreev reflection (CAR), in three device geometries. The first devices studied are lateral …
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Non-Sinusoidal Current -Phase Relations in Superconductor-Ferromagnet-Superconductor Josephson Junctions
… current-phase relation (CPR) of a superconductor-ferromagnet-superconductor (SFS) Josephson junction, and determined that it contains a positive second-harmonic term proportional to sin(2&phis;). The second-harmonic term becomes dominant near Tpi, the temperature at which the first-order term …
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Electrical injection and detection of spin polarization in InSb/ferromagnet nanostructures
… and strong spin-orbit interaction. Using ferromagnetic CoFe, lateral InSb/CoFe devices are fabricated by semiconductor processing techniques. The saturation magnetizations of various CoFe electrodes with different widths are calculated from Hall measurements in which the fringing fields of …
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Spin resolved photoelectron spectroscopy of oxidic half-metallic ferromagnets and oxide-ferromagnet interfaces
… electronic structure of the half-metallic ferromagnetic materials (Fe3O4 and CrO2) and bilayers I/FM (I = Al2O3 or MgO, FM = Fe(110)). Fe3O4 and CrO2 are found to be consistent with half-metallic ferromagnets, for the values investigated, with extraordinary high spin polarization values at …
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Spin-mixing and transport through superconducting interlayers in ferromagnetic Josephson junctions
… at magnetically inhomogeneous superconductor/ferromagnet interfaces, and have a longer decay envelope in a ferromagnet than singlet Cooper pairs (or ’singlet pairs’). In this thesis I investigate ferromagnetic nanopillar Josephson devices with different types of ferromagnetic …
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A study of surface roughness issues in magnetic tunnel junctions
… the interface roughness into the basic Ferromagnet/Insulator/Ferromagnet structure. Experimentally, the surface roughness of the Ni80Fe20 bottom electrode is controlled by applying an rf substrate bias during the deposition. Magnetic tunnel junction elements are fabricated by using …
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Theory and simulation of magnetism and spin transport in semiconductors
<P>A THEORETICAL MODEL OF SPIN-TRANSPORT IN FERROMAGNET-SEMICONDUCTOR HYBRID STRUCTURES WHICH TAKES INTO ACCOUNT THE EFFECTS OF INTERFACE RESISTANCE HAS BEEN PRESENTED. SPIN-INJECTION EFFICIENCY AND MAGNETORESISTANCE WHICH ARE THE KEY PARAMETERS IN ANY SPINTRONICS DEVICE ARE STUDIED IN DETAIL. IT …
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Manipulation of spin textures by unconventional spin torques
… generated at the interface between a metallic ferromagnet and a heavy metal due to the spin Hall effect induced by strong spin orbit interaction. We demonstrate that the spin Hall effect can efficiently amplify or attenuate spin waves in an adjacent ferromagnet, and the efficiency of spin …
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Physics and applications of magnetic interactions in topological insulators
… of the magnetic proximity effect, whereby a ferromagnet placed in proximity to a 3D TI creates a mass gap in the Dirac surface states and generates a quantum anomalous Hall effect (QAHE). Although this platform has long been proposed for technological applications ranging from topological …
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Non-equilibrium spin accumulation in Co2FeMnSi/n-GaAs heterostructures
… studies of non-equilibrium spin accumulation in ferromagnet/n-GaAs heterostructures. This work naturally separates into two main topics: the first is the study of the non-equilibrium electron spin accumulation which is generated electrically by passing a current across the ferromagnet/GaAs …
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Thermal Effects on Spin Currents in Non-Local Metallic Spin Valves
… possibly benefits from the presence of oxidized ferromagnet, which further stimulates interest in thermal spin injection for applications in sensors and pure spin current sources. To investigate contact resistance further we also present work comparing NLSVs with permalloy oxide contacts and …
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Mikroskopischer Ursprung der Austauschkopplung in ferromagnetischen, antiferromagnetischen Schichten
… i.e. the shift of a hysteresis loop of a ferromagnet along the magnetic field axis occurs due to the exchange coupling of the ferromagnet to an antiferromagnet. Its microscopic origin is still under discussion. Available experimental data and the theoretical models for this effect are …
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Phonon-mediated Casimir effect
… propagation of a singe hole in a two-dimensional ferromagnet accompanied by spin-flip processes. We show that an external magnetic field can be used to manipulate the properties of the single-layer system. For easy plain ferromagnets, at saturation value of the external field perpendicular to the …
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Superconducting Proximity Effects and Josephson Coupling in CoFeB Structures
… results that assess the suitability of a ferromagnetic cobalt-iron-boron alloy (CoFeB) for further research and application in ‘superconducting spintronics’ - the field that aims to utilise the distinct physics arising at interfaces between superconducting and magnetic thin films for the …
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Control of Superconductivity in Cuprate/Manganite Heterostructures
… has shown that the spin alignment in an adjacent ferromagnet is capable of suppressing superconductivity. In this project, devices incorporating cuprate/manganite heterostuctres were successfully fabricated to study the effects of spin transport on the high temperature superconductor, YBCO. …
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Spin injection and manipulation in organic semiconductors
… interaction between the organic molecule and the ferromagnet. This interaction ranges from a weak Van der Waals' to a chemical interaction leading to charge transfer, hybridization and other interface chemistry. As a result, the spin-dependent density of states is modified, influencing the spin …
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Active control of superconductivity by means of the ferromagnetic exchange interaction
… of superconductivity in superconductor/ferromagnet (S/F) heterostructures could be modulated by controlling the ferromagnetic exchange interaction in the superconductor. The exchange interaction in the superconductor is the sum of the exchange interaction from the ferromagnetic regions, …
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