Search for dissertations about: "magnetic vortex"

Showing result 1 - 5 of 40 swedish dissertations containing the words magnetic vortex.

2. 1. Tailored Properties of Ferromagnetic Thin Films

   Author : Peter Warnicke; Peter Svedlindh; Peter Grünberg; Uppsala universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; micromagnetics; domain wall; vortex; pinning potential; nanowire; spin dynamics; spin transfer torque; magnetic anisotropy; MFM; Permalloy; PMA; magnetic multilayer; Curie temperature; DMS; GaMnAs; magnetic bioseparation; Engineering physics; Teknisk fysik;

   Abstract : Magnetic thin films and patterned nanostructures have been studied with respect to their magnetic properties using SQUID-magnetometry, magnetic force microscopy, electrical measurements, and micromagnetic calculations. Properties of vortex domain walls, trapped in Permalloy nanowires with artificial constrictions, were investigated experimentally and by numerical calculations. READ MORE

4. 2. Nonlinear dynamics of strongly-bound magnetic vortex pairs

   Author : Artem Bondarenko; Vladislav Korenivski; Gleb Kakazei; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; magnetic vortex; nonlinear mechanics; isolated resonance; nonlinear frequency tuning; chaotic dynamics; parametric interaction; Thiele equation; Monte Carlo simulations; Ito processes; bistability; tunneling magneto-resistance; Magnetisk-virvel; icke-linjär dynamik; isolerad resonans; icke-linjär frekvens-optimering; kaotisk dynamik; parametrisk interaktion; Thiele-ekvation; Monte Carlo-simuleringar; Ito-processer; bistabilitet; tunnelmagneto-resistans.; Fysik; Physics;

   Abstract : This work is a study of nonlinear phenomena in vertically stacked pairs of magnetic vortices. New dynamic regimes are uncovered with a decrease in the inter-vortex separation to below the lateral vortex-core size. READ MORE

5. 3. Phase transitions in magnetic metamaterials

   Author : Björn Erik Skovdal; Björgvin Hjörvarsson; Vassilios Kapaklis; Gunnar K. Pálsson; Peter Schiffer; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Magnetic metamaterials; artificial spin ice; mesospins; magnetic nanostructures; mesoscopic spin systems; multiscale materials; tri-criticality; emergence; edge modes;

   Abstract : Magnetic metamaterials consisting of arrays of densely packed, two-dimensional nanoscale magnetic islands have degrees of freedom on two separate length scales: inside the islands, and among them. These degrees of freedom can be tuned by e.g. size, shape, island separation and lattice geometry. READ MORE

6. 4. Resistive studies of vortices and fluctuations in single crystal YBa2Cu3O7-

   Author : Therese Björnängen; KTH; []
   Keywords : condensed matter physics; high temperature superconductors; YB2Cu3O7-d; untwinned YBCO; oxygen deficiency; superconducting fluctuations; magnetoconductivity; in-plane anisotropy; vortex liquid; vortex solid; vortex correlation;

   Abstract : High-temperature superconductors have been intensely studiedsince the discovery, almost 20 years ago. Their layeredstructure, extreme type-II behavior, large anisotropy, andstrong fluctuations have led to a large number of new andinteresting problems. READ MORE

7. 5. Resonant switching and vortex dynamics in spin-flop bi-layers

   Author : Sergiy Cherepov; Vladislav Korenivski; Thomas Silva; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; spin-dynamics; MRAM; vortex; switching; Condensed matter physics; Kondenserade materiens fysik; Magnetism; Magnetism; Mesoscopic physics; Mesoskopisk fysik;

   Abstract : This thesis is a study of the static and dynamic behavior of the magne-tization in spin-flop bi-layers, which consist of two soft ferromagnetic layerscoupled by dipolar forces through a thin nonmagnetic spacer. The focus ofthe work is three fold: collective spin dynamics in the anti-parallel groundstate; resonant switching in the presence of thermal agitation; and static anddynamic behavior of the system in the vortex-pair state, with a particularemphasis on the interlayer core-core interaction. READ MORE