Sökning: "Magnetic order"

Visar resultat 16 - 20 av 637 avhandlingar innehållade orden Magnetic order.

1. 16. Magnetic properties of transition metal compounds and superlattices

   Författare :Arvid Broddefalk; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Magnetic order; magnetocrystalline anisotropy; interlayer exchange coupling; transition metal compounds; superlattices; Materialvetenskap; Materials science; Teknisk materialvetenskap; Solid State Physics; fasta tillståndets fysik;

   Sammanfattning : Magnetic properties of selected compounds and superlattices have been experimentally studied using SQUID (superconducting quantum interference device) and VSM (vibrating sample magnetometer) magnetometry, neutron diffraction and Mössbauer spectroscopy measurements combined with theoretical ab initio calculations. The magnetic compounds (Fe1-xMx)3P, M=Co or Mn have been studied extensively. LÄS MER

3. 17. Tailoring the magnetic order in mesoscopic spin systems

   Författare :Henry Stopfel; Vassilios Kapaklis; Hjörvarsson Björgvin; Unnar Arnalds; John Cumings; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; artificial spin ice; magnetic nano-structures; mesoscopic spin systems; mesospins; model systems; Shakti; Saint George; interaction modifier; engineering of energy-landscape; multiple energy-scales; Fysik; Physics;

   Sammanfattning : Mesoscopic spin systems can be designed and fabricated using modern nano-fabrication techniques. These systems can contain large numbers of patterned ferromagnetic elements, for which the shape will generally determine their effective mesospin dimensionality. LÄS MER

4. 18. 3D Magnetic Photonic Crystals : Synthesis and Characterization

   Författare :Mei Fang; K.Venkat Rao; Lyubov Belova; Rajeev Ahuja; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; magnetic photonic crystals; photonic band gaps; Fe3O4 nanoparticles; silica; Optical physics; Optisk fysik; Materials science; Teknisk materialvetenskap;

   Sammanfattning : This thesis presents the synthesis methods and the characterizations of magnetic Fe3O4 nanoparticles, silica spheres with Fe3O4 nanoparticles embedded, and three dimensional magnetic photonic crystals (MPCs) prepared from the spheres. The structure, material composition, magnetic and optical properties, photonic band gaps (PBGs), as well as how these properties depend on the concentration of the magnetic nanoparticles, are investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), vibrating sample magnetometer (VSM), superconducting quantum interference device (SQUID), Faraday rotation (FR) and optical spectrophotometers. LÄS MER

5. 19. The Importance of Controlling Composition to Tailor the Properties of Magnetic Thin Films

   Författare :Andreas Frisk; Gabriella Andersson; Tomas Nyberg; Erik Johansson; Sarah Thompson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; FeNi; L10; X-ray diffraction; magnetic anisotropy; magnetron sputtering; thin film; permanent magnets; combinatorial materials science; amorphous materials; magnetic properties of thin films; chemical order; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : Many physical properties, for example structural or magnetic, of a material are directly dependent on elemental composition. Tailoring of properties through highly accurate composition control is possible in thin films. This work exemplifies such tailoring. LÄS MER

7. 20. Magnetic Ordering in Layered Magnets

   Författare :Moreno Marcellini; Björgvin Hjörvarsson; Roger C.C Ward; Uppsala universitet; []
   Nyckelord :Physics; Magnetic thin films and superlattices; Magnetic phase transitions; Polarized neutron reflectometry; Fysik;

   Sammanfattning : The preparation of layered magnets needs the knowledge of growth techniques which are focused on the growth of Fe/V(001) superlattices. Such films have been structurally investigated by X-rays reflectivity and diffraction. LÄS MER