Sökning: "Magnetic domains"

Visar resultat 1 - 5 av 81 avhandlingar innehållade orden Magnetic domains.

  1. 1. Magnetic Heterostructures : The Effect of Compositional Modulation on Magnetic Properties

    Författare :Inna Soroka; Roger Wäppling; Björgvin Hjörvarsson; Rudolf Schäfer; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Magnetism; Sputter deposition; Superlattice; Multilayers; Materialvetenskap; Materials science; Teknisk materialvetenskap;

    Sammanfattning : The effect of compositional modulation on structural and magnetic properties of magnetic heterostructures was explored. The systems under focus were ferromagnetic superlattices Fe81Ni19/Co, metal-insulator multilayers Al2O3/Ni81Fe19, nanoparticles and artificial multilayered pillars. LÄS MER

  3. 2. Modeling and Verification of Ultra-Fast Electro-Mechanical Actuators for HVDC Breakers

    Författare :Ara Bissal; Göran Engdahl; Elena Lomonova; KTH; []
    Nyckelord :Actuators; Armature; Capacitors; Circuit breakers; Coils; Damping; Eddy currents; Elasticity; Electro-mechanical devices; Electromagnetic forces; Finite element methods; HVDC transmission; Image motion analysis; Magnetic domains; Magnetic flux; Magnetic forces; Magnetic materials; Magnets; Thermal analysis; Electrical Engineering; Elektro- och systemteknik;

    Sammanfattning : The continuously increasing demand for clean renewable energy has rekindled interest in multi-terminal high voltage direct current (HVDC) grids. Although such grids have several advantages and a great potential, their materialization has been thwarted due to the absence of HVDC breakers. LÄS MER

  4. 3. Ferromagnetic resonance in films with growth induced anisotropy

    Författare :Sergey Manuilov; Alex Grishin; Boris Kalinikos; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ferromagnetic resonance; magnetic anisotropy; single-ion anisotropy model; ferrites; magnetic epitaxial films; magnetostatic waves; pulsed laser deposition; magnetic alloys; domains; domain wall transformations;

    Sammanfattning : This thesis discusses two different magnetic materials: epitaxial yttrium iron garnet (YIG) and heteromorphous CoFeB-SiO2 films. YIG films were grown by pulse laser deposition (PLD) techniques onto gadolinium gallium garnet (GGG) substrates of (111) and (001) crystal orientations. LÄS MER

  5. 4. Designing order with long-range interactions in mesoscopic magnetic chains

    Författare :Christina Vantaraki; Vassilios Kapaklis; Björgvin Hjörvarsson; Gabriella Andersson; Tapati Sarkar; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetism; mesospins; mesoscopic magnetic chains; magnetic nanostructures; long-range interactions;

    Sammanfattning : This thesis investigates how the low-energy magnetic configuration of a mesoscopic chain can be tuned by geometrical modifications. The magnetic arrays made by single-domain stadium shaped elements positioned side-by-side were fabricated by patterning into a sputtered ferromagnetic thin film. LÄS MER

  7. 5. Ultrafast spin dynamics at the nanoscale : using coherent X-ray and terahertz radiation

    Författare :Nanna Zhou Hagström; Stefano Bonetti; Stefan Eisebitt; Ferran Macià Bros; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; XFEL; small-angle X-ray scattering; X-ray holography; ultrafast magnetism; symmetry-breaking; magnetic domains; terahertz; magnetic field enhancement; metamaterial; time-resolved magneto-optical microscope; Physics; fysik;

    Sammanfattning : The field of ultrafast magnetism is driven by the growing need for faster and more efficient magnetic data storage, which comprises the vast majority of the digital information worldwide. However, after more than two decades of intense research, the understanding of the fundamental physical processes governing the transfer of angular momentum necessary for magnetic switching, is still lacking, partially hampered by the appropriate experimental tools. LÄS MER