Sökning: "Physics with spec. in Atomic"

Visar resultat 11 - 15 av 83 avhandlingar innehållade orden Physics with spec. in Atomic.

1. 11. Theoretical and Computational Studies on the Physics of Applied Magnetism : Magnetocrystalline Anisotropy of Transition Metal Magnets and Magnetic Effects in Elastic Electron Scattering

   Författare :Alexander Edström; Jan Rusz; Olle Eriksson; Patrick Bruno; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Magnetism; Magnetic anisotropy; DFT; Permanent magnets; Electron vortex beams; Electron microscopy; Electron scattering; Multislice methods; Magnetism; magnetisk anisotropi; permanentmagneter; täthetsfunktionalteori; elektronmikroskopi; elektronvirvelstrålar; elektronspridningsteori; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : In this thesis, two selected topics in magnetism are studied using theoretical modelling and computational methods. The first of these is the magnetocrystalline anisotropy energy (MAE) of transition metal based magnets. In particular, ways of finding 3d transition metal based materials with large MAE are considered. LÄS MER

3. 12. Uncovering Magnetic Order in Nanostructured Disordered Materials : A Study of Amorphous Magnetic Layered Structures

   Författare :Panagiotis Korelis; Björgvin Hjörvarsson; Gabriella Andersson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Amorphous Materials; Magnetism; Amorphous Magnetism; Magnetic Measurements; Thin Films; Multilayers; Thin Film Deposition; Sputtering; FeZr Alloys; AlZr Alloys; X-ray Diffraction; Rutherford Backscattering Spectrometry; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : The scope of this thesis is the study of the interplay between structure and magnetism in amorphous materials. The investigations focus on the growth of amorphous layers and the study of the influence of structural disorder and reduced physical extension on the magnetic properties of thin films and multilayers. LÄS MER

4. 13. Quasicrystal Approximants in the RE-Au-SM systems (RE = Gd, Tb, Ho, Yb; SM = Si, Ge) : Syntheses, structures and properties

   Författare :Girma Hailu Gebresenbut; Cesar Pay Gómez; Martin Sahlberg; Torbjörn Gustafsson; Alan I. Goldman; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Quasicrystal approximant; structure; physical property; Chemistry with specialization in Inorganic Chemistry; Kemi med inriktning mot oorganisk kemi; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : In this study, new Tsai-type 1/1 quasicrystal approximants (ACs) in the RE-Au-SM systems (RE = Gd, Tb, Ho, Yb; SM = Si, Ge) were synthesized using high temperature synthesis techniques such as self-flux, arc-melting-annealing and novel arc-melting-self-flux methods. The syntheses not only provided appropriate samples for the intended structural and physical property measurements but could also be adapted to other systems, especially where crystal growth is a challenge. LÄS MER

5. 14. Critical Phenomena and Exchange Coupling in Magnetic Heterostructures

   Författare :Martina Ahlberg; Gabriella Andersson; Björgvin Hjörvarsson; Steve Bramwell; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; phase transitions; critical behavior; 2D XY model; MOKE; magnetic thin films and superlattices; amorphous multilayers; magnetic proximity effects; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : The continuous phase transition in thin magnetic films and superlattices has been studied using the magneto-optical Kerr effect (MOKE) and polarized neutron scattering (PNR).  It has been shown that the critical behavior of amorphous thin films belonging to the 2D XY universality class can be described within the same theory as crystalline sample. LÄS MER

7. 15. Computational Studies of Electron Transport in Nanoscale Devices

   Författare :Henrik Löfås; Rajeev Ahuja; Jan Isberg; Fabian Pauly; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Density functional theory; Molecular electronics; Organosilicon chemistry; Diamond; Molecular switches; Nanoelectrode bridge platform; Molecular cords; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik; Physics with spec. in Atomic; Molecular and Condensed Matter Physics;

   Sammanfattning : In this thesis, a combination of density functional theory (DFT) based calculations and nonequilibrium Green’s functions are employed to investigate electron transport in molecular switches, molecular cords and nanoscale devices.  Molecular electronic devices have been proposed as an approach to complement today’s silicon based electronic devices. LÄS MER