Sökning: "Gilbert damping"

Visar resultat 1 - 5 av 10 avhandlingar innehållade orden Gilbert damping.

1. 1. Gilbert damping of doped permalloy from first principles calculations

   Författare :Fan Pan; Lars Bergqvist; Peter Svedlindh; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Gilbert damping; DFT; Permalloy; SPR-KKR; Spin stiffness; Fysik; Physics;

   Sammanfattning : The dynamic process of how fast a spintronic device can be switched from one state to another is characterized by the Gilbert damping parameter. It has been found that the Gilbert damping along with other intrinsic properties in permalloy, can be tuned by different dopants and doping concentration. LÄS MER

3. 2. Magnetization Dynamics in Ferromagnetic Thin Films : Evaluation of Different Contributions to Damping in Co2FeAl and FeCo Film Structures

   Författare :Serkan Akansel; Peter Svedlindh; Olof Karis; Erik Wahlström; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; spintronics; Gilbert damping parameter; magnetization dynamics; ferromagnetic resonance; Heusler alloys; magnetic thin films; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : Static and dynamic magnetic properties of Co2FeAl and Fe65Co35 alloys have been investigated. Co2FeAl films were deposited at different temperatures and the deposition parameters were optimized with respect to structural and magnetic properties. As a result, a film with B2 crystalline phase was obtained without any post-annealing process. LÄS MER

4. 3. Ultrafast Magnetization Dynamics : Element-selective studies of magnetic alloys using ultra short XUV pulses

   Författare :Rameez Saeed Malik; Olof Karis; Uwe Bovensiepen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; magnetization dynamics; magnetic alloys; HHG; ultrashort laser pulses; magneto-optical Kerr effect MOKE ; Gilbert damping; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : In this thesis, I investigate the ultrafast magnetization dynamics in 3d ferromagnets and their alloys with ultrashort laser pulses. The high harmonics generation (HHG) setup provides extreme-ultraviolet photons with energies 35-72 eV, which is the energy range where 3d metals have their M2,3 absorption edges. LÄS MER

5. 4. Ferromagnetic Resonance as a Probe of Magnetization Dynamics : A Study of FeCo Thin Films and Trilayers

   Författare :Yajun Wei; Peter Svedlindh; Sujeet Chaudhary; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ferromagnetic resonance FMR ; Gilbert damping; magnetic coupling; FeCo;

   Sammanfattning : The high frequency dynamic magnetic responses of FeCo thin films and structures have been investigated mainly using ferromagnetic resonance (FMR) technique.The FMR resonance condition and linewidth are first derived from the dynamic Landau- Lifshitz-Gilbert equation, followed by a study of the conversion between FMR field and frequency linewidths. LÄS MER

7. 5. Relativistic theory of laser-induced magnetization dynamics

   Författare :Ritwik Mondal; Peter M. Oppeneer; Jan Rusz; Olle Eriksson; Paul-Antoine Hervieux; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Relativistic quantum electrodynamics; magneto-optics; spin-orbit coupling; ultrafast demagnetization; inverse Faraday effect; magnetic inertia; Gilbert damping; Fysik; Physics;

   Sammanfattning : Ultrafast dynamical processes in magnetic systems have become the subject of intense research during the last two decades, initiated by the pioneering discovery of femtosecond laser-induced demagnetization in nickel. In this thesis, we develop theory for fast and ultrafast magnetization dynamics. LÄS MER