Journal ArticleDOI
Comparative study of the electronic structure of ordered, partially ordered, and disordered phases of the Cu3Au alloy.
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Etude du changement de structure electronique du a l'augmentation progressive du desordre dans cet alliage fait varier de facon continue le parametre d'ordre de son maximum S=1 a son minimum (S=0).Abstract:
We present a theoretical study of the electronic structure of ordered, partially ordered, and disordered phases of the ${\mathrm{Cu}}_{3}$Au alloy using the scalar-relativistic linear muffin-tin orbitals (LMTO) method in conjunction with the coherent-potential approximation. We study the change in the electronic structure caused by the gradual increase of disorder in the alloy by varying the long-range-order parameter S continuously from its maximum (S=1) to the minimum (S=0) possible value. Calculations for the disordered phase (S=0) are performed with and without relaxation of the lattice. The relaxed-lattice calculation takes into account, in an approximate way, the possible deviations from the ideal lattice structure due to the difference in the sizes of the constituent atoms. As a side issue, we address the problem of transferability of the LMTO parameters of the individual alloy components in the pure crystalline phase to the alloy calculation.read more
Citations
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Journal ArticleDOI
Electronic-structure calculations for amorphous solids using the recursion method and linear muffin-tin orbitals: Application to Fe80B20.
TL;DR: In the present version, the LMTO matrix elements are evaluated in the atomic-sphere approximation (ASA).
Journal ArticleDOI
First-principles study of the magnetic structures of ordered and disordered Mn-Ir alloys
Abstract: Electronic and magnetic structures of \ensuremath{\gamma}-phase disordered ${\mathrm{Mn}}_{100\ensuremath{-}x}{\mathrm{Ir}}_{x}$ alloys including ${L1}_{2}$-type ordered ${\mathrm{Mn}}_{3}\mathrm{Ir}$ alloy have been investigated by the first-principles approach using the tight-binding (TB) linear muffin tin orbital (LMTO) method. For the ${L1}_{2}$-type ordered ${\mathrm{Mn}}_{3}\mathrm{Ir}$ alloy, a triangular $(T1)$ magnetic structure is considered to be stable, reflecting in a dip structure around the Fermi level in the density of states. For the \ensuremath{\gamma}-phase disordered ${\mathrm{Mn}}_{3}\mathrm{Ir}$ alloy, on the other hand, the most stable structure is suggested to be the $3Q$ structure among the multiple-Q spin density wave (MSDW) structures. The N\'eel temperature is estimated to be about 735 K from the effective exchange constant ${J}_{0},$ in good agreement with the experimental value of about 730 K. With decreasing Ir concentration in the \ensuremath{\gamma}-phase disordered ${\mathrm{Mn}}_{100\ensuremath{-}x}{\mathrm{Ir}}_{x}$ alloys, the transition from the $3Q$ to the $2Q$ structure takes place in the vicinity of $x=13$ under the constant lattice parameters with the axial ratio of $c/a=1.$ This critical concentration x is close to the observed concentration at which the axial ratio changes from $c/a=1$ to $c/ag1.$ However, it should be stressed that these two critical concentrations do not necessarily coincide with each other, that is, the critical concentration of the magnetic structure transition is lower than that of the lattice distortion. This theoretical expectation has been verified by the experimental structural and magnetic data.
Book
Nanoalloys : synthesis, structure and properties
TL;DR: In this paper, the structure and morphology of bimetallic nanoparticles were investigated using X-ray scattering methods and transmission electron microscopy (TEEM) for atomic-scale characterization of nano-alloys.
Journal ArticleDOI
Electronic structure of random binary alloys
TL;DR: In this article, an application of the augmented space recursion technique for binary disordered alloys is presented, which allows us to incorporate effects like clustering, short-ranged order and off-diagonal disorder arising out of size mismatch and consequent lattice distortions.
Journal ArticleDOI
Thermal and mechanical properties of Cu–Au intermetallic alloys
TL;DR: In this article, the thermal and mechanical properties of CuxAu1−x are analyzed by using the molecular dynamics simulation, and the effects of temperature and concentration on the physical properties of the Cux Au 1−x were analyzed.