Book ChapterDOI
Disordered Alloys and Their Surfaces: The Coherent Potential Approximation
Ilja Turek,Josef Kudrnovský,Václav Drchal +2 more
- Vol. 535, pp 349-378
TLDR
In this article, a recently developed ab initio approach to the electronic structure of substitutionally disordered alloys and their surfaces is reviewed, based on the tight-binding linear muffin-tin orbital (TB-LMTO) method in the atomic sphere approximation which provides a physically transparent solution of the one-electron problem in metallic materials, and the coherent potential approximation (CPA) for a mean-field treatment of the substitutional randomness, and surface Green functions for a proper description of the true semi-infinite geometry of surfaces and interfaces.Abstract:
A recently developed ab initio approach to the electronic structure of substitutionally disordered alloys and their surfaces is reviewed. It is based on (i) the tight-binding linear muffin-tin orbital (TB-LMTO) method in the atomic sphere approximation which provides a physically transparent solution of the one-electron problem in metallic materials, (ii) the coherent potential approximation (CPA) for a mean- field treatment of the substitutional randomness, and (iii) the surface Green functions for a proper description of the true semi-infinite geometry of surfaces and interfaces. Theoretical formulation of fundamental electronic quantities, both site-diagonal (charge densities, densities of states) and site non-diagonal (the Bloch spectral functions) is presented. Transformation properties of the LMTO-CPA theory as well as specific problems of application of the local density approximation to random alloys are briefly discussed and basic algorithms employed in the numerical implementation of the formalism are described.read more
Citations
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Journal ArticleDOI
Exchange interactions, spin waves, and transition temperatures in itinerant magnets
TL;DR: In this paper, an ab initio two-step procedure to determine exchange interactions, spin-wave spectra, and thermodynamic properties of itinerant magnets is presented, and the applicability of the developed scheme is illustrated by selected properties of various systems such as transition and rare-earth metals, disordered alloys including diluted magnetic semiconductors, ultrathin films, and surfaces.
Journal ArticleDOI
Relativistic LMTO method for systems of light elements
TL;DR: In this article, the theoretical background of an approximate treatment of relativistic effects within the TB linear muffin-tin orbital (LMTO) method for ab-initio electronic structure calculations of solids is reviewed.
Journal ArticleDOI
Spin-mixing conductances of metallic and half-metallic magnetic layers
Ilja Turek,Karel Carva +1 more
TL;DR: The spin-mixing conductance of a thin ferromagnetic layer attached epitaxially to two semi-infinite non-magnetic metallic leads is formulated in terms of non-equilibrium Green's functions and serious doubts are thrown on the general validity of two features: fast convergence of the spin- Mixing Conductance with increasing thickness of the magnetic layer and negligible values of the imaginary part of thespin-mixed conductance as compared to the real part.
Journal ArticleDOI
Tunnelling anisotropic magnetoresistance of Fe/GaAs/Ag(001) junctions from first principles: Effect of hybridized interface resonances
Rudolf Sykora,Ilja Turek +1 more
TL;DR: Results of first-principles calculations of the Fe/GaAs/Ag(001) epitaxial tunnel junctions reveal that hybridization of interface resonances formed at both interfaces can enhance the tunnelling anisotropic magnetoresistance (TAMR) of the systems.
Journal ArticleDOI
Effect of P-anion codoping on the Curie temperature of GaMnAs diluted magnetic semiconductors
TL;DR: In this paper, a parameter-free theory of the Curie temperature of GaMnAs alloy samples with a very small content of P atoms prepared by ion-implanted pulsed laser melting (II-PLM) was presented.
References
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Journal ArticleDOI
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TL;DR: In this paper, the minimal base of muffin-tin orbitals is transformed exactly into a tight-binding base and the linear transformations, the orbitals, and the Hamiltonian overlap are expressed in terms of one matrix, the canonical structure matrix.
Journal ArticleDOI
Coherent-Potential Model of Substitutional Disordered Alloys
TL;DR: In this paper, a substitutional alloy based on the concept of an effective or coherent potential was introduced, which, when placed on every site of the alloy lattice, will simulate the electronic properties of the actual alloy.
Journal ArticleDOI
Highly convergent schemes for the calculation of bulk and surface Green functions
TL;DR: In this article, the surface and bulk densities of states of a solid described by stacking of principal layers are obtained by means of an iterative procedure which allows the inclusion of 2n layers after n iterations, and simultaneous calculation of the Green functions for both the 'right' and 'left' surfaces as well as for the bulk (or central) principal layer, and the use of imaginary parts eta as small as one wishes in the energy without any large increase in computing time.