Sökning: "magnetic switching"

Visar resultat 1 - 5 av 66 avhandlingar innehållade orden magnetic switching.

  1. 1. Magnetic Refrigeration for Near Room-Temperature Applications

    Författare :Behzad A Monfared; Björn Palm; Joachim Claesson; Andrew Rowe; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Magnetic Refrigeration; Magnetic; Cooling; Magnetocaloric; Life Cycle Assessment; Modeling; Simulation; Optimization; Regeneration; Active Magnetic Regeneration; Bonded Regenerator; Heat Switch; Thermal Diode; Peltier; Solid-State; Prototype; Magnetisk Kylteknik; Magnetisk; Kylning; Magnetokalorisk; Livscykela-nalys; Modellering; Simulering; Optimering; Regenerering; Aktiv Mag-netisk Regenerering; Bunden Regenerator; Värmebrytare; Termodiod; Peltier; Solid-State; Prototyp; Energy Technology; Energiteknik;

    Sammanfattning : Refrigeration plays a crucial role in many different sectors and consumes about 17% of the electricity produced globally. This significant energy consumption implies large share of refrigeration in primary energy consumption and other environmental impacts. LÄS MER

  3. 2. Magnetic deflagration and detonation in crystals of nanomagnets

    Författare :Oleksii Iukhymenko; Claude Dion; Javier Tejada; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nanomagnets; magnetic deflagration; front instability; Zeeman energy; magnetic instability; magnetic detonation; weak detonation; Physics Of Matter; materiefysik;

    Sammanfattning : In this thesis we cover the dynamics of the macro magnetic transformations (spin avalanches) in crystals of molecular nanomagnets, also known as magnetic deflagration and detonation.Taking a single-molecule Hamiltonian, we calculate the dependence of Zeeman energy and the activation energy as a function of an external magnetic field at different angles relative to the easy axis of the crystal. LÄS MER

  4. 3. Amorphous Magnetic Materials : A Versatile Foundation for Tomorrow’s Applications

    Författare :Sebastian George; Gabriella Andersson; Björgvin Hjörvarsson; Fridrik Magnus; Elizabeth Blackburn; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Amorphous; Magnetism; Rare Earth; Transition Metal; RE-TM; Thin Film; TbCo; SmCo; FeZr; CoFeZr;

    Sammanfattning : Amorphous magnetic materials exhibit a number of key differentiating properties with respect to crystalline magnets. In some cases, the differences may simply be in the values of macroscopic properties such as saturation magnetization, coercivity, Curie temperature, and electrical conductivity. LÄS MER

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

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

    Sammanfattning : 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. LÄS MER

  7. 5. Atomistic Spin Dynamics, Theory and Applications

    Författare :Johan Hellsvik; Olle Eriksson; Lars Nordström; Ulrich Nowak; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ab initio calculations; spin dynamics; magnetization; magnetic switching; diluted magnetic semiconductors; spin glasses; ferromagnetic relaxation; ferrimagnets; antiferromagnets; Magnetism; Magnetism; Condensed matter physics; Kondenserade materiens fysik; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : The topic of this Thesis is magnetization dynamics on atomic length scales. A computational scheme, Atomistic Spin Dynamics, based on density functional theory, the adiabatic approximation and the atomic moment approximation is presented. LÄS MER