Sökning: "magnetic semiconductors"

Visar resultat 11 - 15 av 52 avhandlingar innehållade orden magnetic semiconductors.

1. 11. Transmission Electron Microscopy of Semiconductor Nanowires

   Författare :Magnus Larsson; Centrum för analys och syntes; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Nanowires; magnetic resonance; supraconductors; magnetic and optical properties; electrical; Condensed matter:electronic structure; fasjämvikt; kristallografi; egenskaper termiska och mekaniska ; crystallography; phase equilibria; Kondenserade materiens egenskaper:struktur; akustik; Condensed matter:stucture; thermal and mechanical properties; optics; acoustics; Elektromagnetism; optik; Electromagnetism; Scanning Tunneling Microscopy; Nanomaterials; III-V Semiconductors; Transmission Electron Microscopy; Inorganic chemistry; Oorganisk kemi; relaxation; spectroscopy; Kondenserade materiens egenskaper:elektronstruktur; egenskaper elektriska; magnetiska och optiska ; supraledare; magnetisk resonans; spektroskopi; materialteknik; Material technology; Materiallära; Semiconductory physics; Halvledarfysik;

   Sammanfattning : Semiconductor nanowires are studied by using transmission electron microscopy (TEM) based methods in this work. In the first section, the growth mechanism of gallium arsenide nanowires grown by chemical beam epitaxy is investigated. The nanowires are epitaxially grown from a gallium arsenide substrate by using gold seed particles as catalysts. LÄS MER

3. 12. New Materials for Spintronics : Electronic structure and magnetism

   Författare :Ronny Knut; Olof Karis; Biplab Sanyal; Hermann Durr; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spintronics; X-ray photoemission; XPS; XMCD; XAS; magnetic semiconductors; HIKE; HAXPES; multilayer; monte carlo; magnetism; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

   Sammanfattning : Materials exhibiting new functionalities due to interdependent electric (e.g. conductivity) and magnetic properties are potentially interesting for spintronics applications. LÄS MER

4. 13. Novel room temperature ferromagnetic semiconductors

   Författare :Amita Gupta; KTH; []
   Nyckelord :;

   Sammanfattning : In today's information world, bits of data are processed bysemiconductor chips, and stored in the magnetic disk drives.But tomorrow's information technology may see magnetism (spin)and semiconductivity (charge) combined in one 'spintronic'device that exploits both charge and 'spin' to carry data (thebest of two worlds). LÄS MER

5. 14. Excitons in a high magnetic field

   Författare :Alexandre V. Petrov; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physics; Fysik; Physics; Fysik; fysik; Physics;

   Sammanfattning : The interaction of excitons with each other and with charged impurities has been studied in a high magnetic field when the distance between the Landau levels is greater than the Coulomb unit of energy, in the frame of the model suitable for description of Wannier excitons in semiconductors. The analytical expressions for the pair interaction potential between hydrogenlike excitons in a high magnetic field are derived for the triplet and singlet terms. LÄS MER

7. 15. Electronic Structure and Statistical Methods Applied to Nanomagnetism, Diluted Magnetic Semiconductors and Spintronics

   Författare :Lars Bergqvist; Olle Eriksson; Warren Pickett; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; spintronics; magnetism; Monte Carlo; critical temperature; exchange interactions; percolation; disorder; noncollinear; electronic structure; Materialvetenskap; Materials science; Teknisk materialvetenskap;

   Sammanfattning : This thesis is divided in three parts. In the first part, a study of materials aimed for spintronics applications is presented. More specifically, calculations of the critical temperature in diluted magnetic semiconductors (DMS) and half-metallic ferromagnets are presented using a combination of electronic structure and statistical methods. LÄS MER