Sökning: "diluted magnetic semiconductors"

Visar resultat 1 - 5 av 11 avhandlingar innehållade orden diluted magnetic semiconductors.

  1. 1. Computational Material Design : Diluted Magnetic Semiconductors for Spintronics

    Författare :Lunmei Huang; Rajeev Ahuja; Walter Temmerman; Uppsala universitet; []
    Nyckelord :Physics; Density functional theory; Diluted magnetic semiconductor; Ferromagnetism; Defect; Phase transition; High pressure; Thermal elastic constant; Fysik;

    Sammanfattning : The present thesis deals with the application of ab-initio electronic structure calculations based on density functional theory for material design.The correlation between magnetic properties and electronic structures has been investigated in detail for diluted magnetic semiconductors (DMS), which have promising application for spintronics devices. LÄS MER

  3. 2. Magnetism of Semiconductors and Metallic Multilayers

    Författare :Victor Stanciu; Per Nordblad; Peter Svedlindh; Poul Erik Lindelof; Uppsala universitet; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Materials science; Magnetic order; Curie temperature; magnetic anisotropy; diluted magnetic III-V semiconductors; metallic magnetic multilayers; interlayer exchange coupling; Materialvetenskap; Materials science; Teknisk materialvetenskap;

    Sammanfattning : Magnetic properties of diluted magnetic semiconductors and magnetic metallic multilayers are investigated by SQUID magnetometry. By doping GaAs with magnetic Mn2+ ions under well defined growth conditions, one obtains a diluted magnetic semiconductor, (Ga,Mn)As, in which the randomly-distributed magnetic ions act as acceptor centers. LÄS MER

  4. 3. Quantum mechanical models of nanomagnetism in transition metal clusters and diluted magnetic semiconductors

    Författare :Olof Strandberg; Matematisk fysik; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; diluted magnetic semiconductors; Mn As; Ga; transition metal clusters; magnetic anisotropy; Nanomagnetism; quantum geometric phases; Chern numbers; effective spin Hamiltonians; dimers;

    Sammanfattning : This dissertation investigates nanomagnetism in small transition metal clusters and the diluted magnetic semiconductor (Ga,Mn)As. We derive quantum mechanical models aimed at a realistic description of the low energy physics in these systems. LÄS MER

  5. 4. Atomistic Spin Dynamics, Theory and Applications

    Författare :Johan Hellsvik; Olle Eriksson; Lars Nordström; Ulrich Nowak; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ab initio calculations; spin dynamics; magnetization; magnetic switching; diluted magnetic semiconductors; spin glasses; ferromagnetic relaxation; ferrimagnets; antiferromagnets; Magnetism; Magnetism; Condensed matter physics; Kondenserade materiens fysik; Physics with spec. in Atomic; Molecular and Condensed Matter Physics; Fysik med inriktning mot atom- molekyl- och kondenserande materiens fysik;

    Sammanfattning : The topic of this Thesis is magnetization dynamics on atomic length scales. A computational scheme, Atomistic Spin Dynamics, based on density functional theory, the adiabatic approximation and the atomic moment approximation is presented. LÄS MER

  7. 5. 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