Thermoactivated structure rearrangements in a binary CuAu alloy under deviation from stoichiometry

Abstract

Thermoactivated structure rearrangements of a binary CuAu alloy at the micro-, meso-, and macrolevels are investigated under deviation from stoichiometry. Mechanisms of these rearrangements at the micro-, meso-, and macrolevels are identified.

Thermoactivated structure rearrangements in a binary CuAu3 alloy under deviation from stoichiometric composition

“…The principal mechanism of structural transformations in the early stage of the process of ordering is formation of antiphase domains [10][11][12][13][14][15][16][17][18][19][20][21]. In the course of simulation, all four types of domains are formed from the initial disordered state at the temperature ~200 K in all the cases under study.…”

“…where k is the Boltzmann constant, Т is the temperature, A is the normalization factor ensuring that the normalization condition is fulfilled (the sum of probabilities of hopping for the atoms located in the first and second coordination spheres with respect to the site is equal to unity, i.e., In order to identify the phases formed in the course of structural changes (here А 3 В, АВ, АВ 3 and those of pure components), we used an approach based on determining the number of atomic pair bonds in the first coordination sphere corresponding to each structure formed [10,11]. This implies that the А 3 В phase structure is found for an A kind atom as the number of its bonds in the first sphere А-А, which is equal to 4, and А-B -8, while for the B kind atom the number of bonds A-В is 12.…”

“…The studies of ordering -disordering processes in condensed systems at the micro-, meso-, and macrolevels simultaneously have begun comparatively recently [10][11][12][13][14]. In [10][11][12][13][14][15][16][17][18], the authors investigated peculiarities of ordering -disordering for the case of high symmetry states of binary alloys (such as Cu 3 Au with superstructure L1 2 ) and in a classical anisotropic state (such as CuAu with superstructure L1 0 ) as a function of temperature and composition.…”

“…In [10][11][12][13][14][15][16][17][18], the authors investigated peculiarities of ordering -disordering for the case of high symmetry states of binary alloys (such as Cu 3 Au with superstructure L1 2 ) and in a classical anisotropic state (such as CuAu with superstructure L1 0 ) as a function of temperature and composition. To complete investigations of ordering in a classical Cu-Au system, one has to study orderingdisordering processes in the alloy compositions close to that of CuAu 3 .…”

Sedimentation of nanoparticles in the field of centrifugal forces

“…From this perspective, it is important to look for ways and scientific principles forming the basis of technologies for classification and differentiation of particles by their size. The most advanced solution to meet these challenges is the use of physical and mathematical models [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. Let us follow this approach to solve the problem of particle differentiation by size and shape.…”