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Descripción
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| Nanostructured magnetic systems such as nanoparticles, nanowires, multilayers and arrays of nanoelements have drawn a lot of attention in recent years, mainly due to their technological relevance, specially for applications related to magnetic storage, miniaturization of sensors and the so-called magnetoelectronic devices. These systems are characterized by having at least one of its morphological dimensions smaller or of the order of the exchange length, roughly corresponding to the domain wall width (typically a few tens of nanometers for magnetic transition metals), which brings about new magnetization processes, different from those occurring in bulk materials. Both from the point of view of the implementation of actual devices and of the progress in understanding this new phenomenology, it is important to design reliable, repetitive nanostructuring processes, combining good resolution in the nanometer scale with a minimum influence of chemical, structural and morphological imperfections on the final magnetic properties. These issues are crucial because those defects are generally uncontrolled and they might play a fundamental role in the magnetization mechanisms of nanoelements. Consequently, it is highly desirable to customize simple series of well controlled nanoelement arrays exhibiting magnetization processes independent of features arising from the imperfections introduced upon nanostructuring. This thesis studies the influence on the magnetization processes of the structural features of different arrays of nanostructures with two types of motifs, nanowires and antidots (non magnetic holes), fabricated in epitaxial Au (001)/Fe (001)/Mg (001) films, 25 nm thick approximately, grown by Pulsed Laser Deposition (PLD). This work includes a thorough task of fabrication of the arrays by means of different techniques, Focused Ion Beam (FIB) and Electron Beam Lithography (EBL) using either negative or positive resist, as well as a detailed structural and chemical characterization of the films and the arrays with a wide variety of techniques: X-ray Diffraction and Reflectometry (XRD and XRR), Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM) and X-ray Photoelectron Spectroscopy (XPS). | |
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Internacional
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Si |
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ISBN
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Tipo de Tesis
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Doctoral |
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Calificación
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Sobresaliente cum laude |
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Fecha
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23/07/2010 |