Sökning: "demagnetization"

Visar resultat 21 - 25 av 28 avhandlingar innehållade ordet demagnetization.

1. 21. Magnetization dynamics of complex magnetic materials by atomistic spin dynamics simulations

   Författare :Raghuveer Chimata; Biplab Sanyal; Olle Eriksson; Koopmans Bert; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ultrafast remagnetization; ultrafast dynamics; magnetism; multiferroics; amorphous alloys; DFT; spinels magnetostriction; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : In recent years, there has been an intense interest in understanding the microscopic mechanism of laser induced ultrafast magnetization dynamics in picosecond time scales. Magnetization switching on such a time scale has potential to be a significant boost for the data storage industry. LÄS MER

3. 22. Modeling of losses in power transformers from dc to the low kilohertz range

   Författare :Julius Krah; Göran Engdahl; Roland Eriksson; Anthony Moses; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Electrical power technology; power transformer; losses; magnetic hysteresis; magnetic measurement systems; medium frequency; eddy currents; skin effect; thermal diffusion; Elkraftteknik; Electric power engineering; Elkraftteknik;

   Sammanfattning : The development of HVDC converters, local generation and tractions systems increases the demand for power converters. While a lot of studies have been conducted on the power electronics, there are still open questions concerning the contained power transformer that operates at a few kilohertz. LÄS MER

4. 23. Spin dynamics in the terahertz regime

   Författare :Kumar Neeraj; Stefano Bonetti; Markus Kowalewski; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; fysik; Physics;

   Sammanfattning : It is known that the use of conventional optical lasers for the study of ultrafast magnetization dynamics imparts heat to the materials under study, which creates a highly non equilibrium state and masks the fundamental coupling processes leading to ultrafast demagnetization. In order to understand, control and manipulate the dynamics of spins in magnetic systems a new kind of radiation called terahertz (THz) is starting to be used in recent years. LÄS MER

5. 24. Spin Vortices, Interlayer Exchange, and Magnetocalorics in Multilayers

   Författare :Milton Persson; Vladislav Korenivski; David B. Haviland; Coriolan Tiusan; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spin vortex pairs; bimerons; RKKY; finite size effects; nanostructure magnetocalorics; atomistic spin dynamics; nanocalorimetry; Spinvirvelpar; bimeron; RKKY; finita storlekseffekter; magnetkalorimetri i nanostrukturer; atomistisk spindynamik; nanokalorimetri; Material and Nano Physics; Material- och nanofysik;

   Sammanfattning : In this thesis we study strongly coupled pairs of spin vortices, in a configurationsuch that the cores attract while external fields act to pull them apart, with potential applications in magnetic random access memory (MRAM) and oscillators.Inertial decoupling of the cores has been studied and can be achieved with weak nanosecond pulses by the help of anharmonicity. LÄS MER

7. 25. Terahertz spin dynamics in metallic thin film ferromagnets

   Författare :Kumar Neeraj; Stefano Bonetti; Andreas Rydh; Michael Farle; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Terahertz; ultrafast magnetism; spin dynamics; spin nutation; magnetization switching; fysik; Physics;

   Sammanfattning : The past two decades have witnessed an increasing interest in understanding and controlling materials at the pico- and femtosecond time scales, the so-called ultrafast regime. Among the broad field of condensed matter physics, magnetism and magnetic materials have attracted much interest both from a fundamental and an applied perspective. LÄS MER