Sökning: "electron scattering mechanisms"

Visar resultat 1 - 5 av 50 avhandlingar innehållade orden electron scattering mechanisms.

  1. 1. Theoretical and Computational Studies on the Physics of Applied Magnetism : Magnetocrystalline Anisotropy of Transition Metal Magnets and Magnetic Effects in Elastic Electron Scattering

    Författare :Alexander Edström; Jan Rusz; Olle Eriksson; Patrick Bruno; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetism; Magnetic anisotropy; DFT; Permanent magnets; Electron vortex beams; Electron microscopy; Electron scattering; Multislice methods; Magnetism; magnetisk anisotropi; permanentmagneter; täthetsfunktionalteori; elektronmikroskopi; elektronvirvelstrålar; elektronspridningsteori; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : In this thesis, two selected topics in magnetism are studied using theoretical modelling and computational methods. The first of these is the magnetocrystalline anisotropy energy (MAE) of transition metal based magnets. In particular, ways of finding 3d transition metal based materials with large MAE are considered. LÄS MER

  3. 2. Monte Carlo simulation of electron transport in semiconducting zigzag carbon nanotubes

    Författare :Kannan Thiagarajan; Ulf Lindefelt; Hans-Erik Nilsson; Michele Goano; Mittuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Carbon nanotubes; Monte Carlo method; drift velocity; mobility; electron-phonon scattering; and electron-defect scattering.;

    Sammanfattning : Since the advent of nanoscale material based electronic devices, there has been a considerable interest in exploring carbon nanotubes from fundamental science and technological perspectives. In carbon nanotubes, the atoms form a cylindrical structure with a diameter of the order 1nm. LÄS MER

  4. 3. Charge carrier transport in field-effect transistors with two-dimensional electron gas channels studied using geometrical magnetoresistance effect

    Författare :Isabel Harrysson Rodrigues; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; low-field mobility; high-electron-mobility transistor; velocity saturation; quasi-ballistic charge carrier transport; two-dimensional electron gas; charge carrier scattering mechanisms; geometrical magnetoresistance; low noise and high frequency applications; velocity peak; graphene field-effect transistor; charge carrier trans- port;

    Sammanfattning : During the last decades, significant efforts have been made to exploit the excellent and promising electronic properties exhibited by field-effect transistors (FETs) with two-dimensional electron gas (2DEG) channels. The most prominent representatives of this class of devices are high-electron-mobility transistors (HEMTs) and graphene field-effect transistors (GFETs). LÄS MER

  5. 4. Electron-Phonon Interactions in Transition Metal Oxides Studied by Resonance Raman Scattering

    Författare :Jakob Andreasson; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Franck-Condon; Fr ohlich interaction; higher order scattering; perovskite; transition metal oxide; two-phonon; oxygen breathing mode; Raman spectroscopy;

    Sammanfattning : In this thesis, studies of strong electron-phonon interactions in a number of transition metal oxides are presented. Two different electron-phonon interaction mechanisms are identified; Franck-Condon scattering and infrared active longitudinal optical (IR LO) two-phonon activation. LÄS MER

  7. 5. Coupling mechanisms in scattering reactions involving small molecular systems

    Författare :Patrik Hedvall; Åsa Larson; Magnus Gustafsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Theoretical Physics; teoretisk fysik;

    Sammanfattning : In this thesis, theoretical ab initio treatments of two-body molecular collision reactions are studied, having in common that the interaction region including all coupling mechanisms driving the reaction amounts to a molecular description. The main goal is to gain an understanding in the underlying coupling mechanisms involved in these reactions. LÄS MER