Theoretical Descriptions of Complex Magnetism in Transition Metals and Their Alloys.

• Superior document: Linköping Studies in Science and Technology. Dissertations Series ; v.1452
• Author: Ekholm, Marcus.
• Place / Publishing House: Linköping : : Linkopings Universitet,, 2012.; {copy}2012.
• Year of Publication: 2012
• Edition: 1st ed.
• Language: English
• Series: Linköping Studies in Science and Technology. Dissertations Series
• Physical Description: 1 online resource (146 pages)

Table of Contents

• Intro
• I Introduction
• Computational Materials Science
• From the beginning
• Crystal lattice
• Chemical ordering
• Phase stability
• The electron liquid
• Electron correlations
• The Fermi surface
• The quasiparticle picture
• Magnetism
• The electron magnetic moment
• Atomic magnetism
• Effects of the crystal field
• Transition metal magnetism
• Collective electron ferromagnetism
• Ferromagnetic metals
• Hyperfine interactions
• Magnetic order
• Ferromagnets
• Antiferromagnets
• Spin spirals
• Influence of pressure
• Finite temperature magnetism
• Excitations in the ordered regime
• The paramagnetic state
• II Methodology
• An ab initio approach
• The interacting many-body quantum system
• The external potential
• Electron interactions
• The uniform electron liquid
• Electronic Structure Calculations
• Spin Density Functional Theory
• The Kohn-Sham equations
• Exchange and correlation approximations
• Local spin density approximation
• Generalised gradient approximations
• Relativistic forms
• Non-zero temperature
• Performance of exchange-correlation functionals
• Equilibrium properties
• Finite temperature
• Strong correlations
• Computational Methods for the Kohn-Sham Equations
• Hamiltonian-based methods
• Augmented Plane Waves
• Projector Augmented Waves
• Green's function method
• Exact Muffin-Tin Orbitals
• Modelling random alloy potentials
• Special quasirandom structures
• Coherent Potential Approximation
• Locally Self-Consistent Green's function method
• Dynamical Mean Field Theory
• Quantum impurity model
• The local Green's function
• The impurity Green's function
• Self-consistency cycle
• LDA+DMFT
• Model Hamiltonians for finite temperature simulations
• Statistical simulations of configurations
• The Heisenberg Hamiltonian
• Disordered Local Moments.
• Cluster expansion of configurational energy
• Screened Generalised Perturbation Method
• III Discussion
• Results
• Fe-Mn
• Elastic properties FeMn alloys
• Fe-Ni
• Influence of the local environment on hyperfine fields
• Magnetic excitations and chemical phase stability
• High pressure
• NiMnSb
• Stability of (Ni,Mn)MnSb-alloys
• Conclusions and outlook
• Units
• Computational details of unpublished calculations
• Charge density and DOS
• Comparing LSDA and PBE for Fe
• Spin matrices
• Bibliography
• Index
• List of Publications
• Article I Structural and magnetic ground-state properties of -FeMn alloys from ab initio calculations
• Article II Influence of chemical composition and magnetic effects on the elastic properties of fcc Fe-Mn alloys
• Article III Ab initio lattice stability of fcc and hcp Fe-Mn random alloys
• Article IV The influence of additions of Al and Si on the lattice stability of fcc and hcp Fe-Mn random alloys
• Article V Elastic properties of fcc Fe-Mn-X (X= Al, Si) alloys studied by theory and experiment
• Article VI Supercell Calculations of Hyperfine Interactions in Transition Metal Alloys
• Article VII Importance of Thermally Induced Magnetic Excitations in First-principles Simulations of Elastic Properties of Transition Metal Alloys
• Article VIII Influence of the Magnetic State on the Chemical Order-DisorderTransition Temperature in Fe-Ni Permalloy
• Article IX Importance of correlation effects in hcp iron revealed by a pressure-induced electronic topological transition
• Article X Configurational thermodynamics of Fe-Ni alloys at Earth's core conditions
• Article XI Energetics and magnetic impact of 3d-metal doping of thehalf-metallic ferromagnet NiMnSb
• Article XII Ab initio calculations and synthesis of the off-stoichiometric half-Heusler phase Ni1-xMn1+xSb.