Ab Initio Simulations of Transition Metal Alloys: Towards the Multiscale Modeling

The present thesis concerns applications of first principles electronic structure calculations in conjunction with methods of statistical mechanics for simulations of transition metal alloys both in the bulk and at surfaces.A fully relativistic generalization of the exact muffin-tin orbitals (EMTO) method has been developed. The method accurately takes into account spin-orbit coupling and allows one to calculate orbital polarization and magneto-crystalline anisotropy in magnetic systems as well as increasing the range of applicability of the EMTO method to heavy elements. A new direct-exchange Monte Carlo (DEMC) method has been proposed…


1 Introduction
I Computational techniques
2 Ab initio methods
2.1 The one-electron equation
2.2 The LMTO method
2.3 The Green’s function method and the coherent potential approx-imation
2.4 Beyond AS and single-site approximations
2.5 Surface LMTO-CPA method
3 The fully relativistic ab initio techniques
3.1 The Dirac equation for MT-shape of potential and magnetic field
3.2 The fully-relativistic LMTO method for non-magnetic systems
3.3 The fully-relativistic EMTO method for spin-polarized systems
3.3.1 Screened spin-spherical waves
3.3.2 Partial waves
3.3.3 EMT-orbitals and kink matrix
3.3.4 Charge and spin densities
4 Effective interatomic interactions
4.1 Occupation numbers and effective Hamiltonians
4.2 The Connolly-Williams method
4.3 Screened generalized perturbation method
4.4 One-point potentials
4.5 The local relaxations
5 Statistical-mechanical simulations
5.1 Bulk Monte Carlo method
5.2 Direct exchange Monte Carlo method for surfaces
II Applications
6 Fully-relativistic simulations of bulk alloys
6.1 Relativistic corrections to CLS
6.2 Spin and orbital magnetization of FeCo alloys
7 Thin Ni and Co films on Cu surfaces
7.1 Properties of Ni monolayer on Cu substrate
7.2 Magnetic properties of a Co/Cu/Ni trilayer on the Cu(100) surface
8 Computation of bulk phase diagrams
8.1 Vacancy ordering in the in substoichiometric titanium carbides TiCx
9 Surface segregations
9.1 Surface segregations in NiPt and NiPd disordered alloys
9.2 Antisite-defect-induced surface segregation in ordered NiPt alloy
9.3 Surface segregations and surface magnetism in V-based transi-tion metal alloys
9.3.1 Surface magnetization of PdV alloys
9.3.2 Surface magnetization of MoV alloys

Author: Pourovskii, Leonid

Source: Uppsala University Library

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