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.