Eremin A.M., Zakharov P.V., Starostenkov M.D., Manakov N.A.
ON THE QUESTION ON THE STATISTICAL COMPARISON OF ACCURATE DISCRETE BREEZERS WITH QUASI-BREEZE MODEL SOLUTIONS OF A₃B STEHOMETRY CRYSTAL ^{[№ 5 ' 2018]}
The method of molecular dynamics is used to perform a statistical comparison of exact discrete breathers with quasi-breather model solutions of the A3B stoichiometry crystal, using the example of Pt₃Al. A phonon spectrum of this model crystal is obtained, the dependences of the root-mean-square deviation, the coefficient of variation, and the mean frequency of the model quasi-breather on the time of its existence are obtained. Also within the framework of this model, the following statistical characteristics and dependencies were calculated: a grouped statistical series of absolute and relative frequencies, a polygon of absolute and relative frequencies, a histogram of relative frequencies, an empirical distribution function, an estimate of the mathematical expectation and variance of the original sample. Analysis of statistical data allows us to conclude that in the model under consideration using the interatomic interaction potential obtained by the immersed atom (EAM) method, the quasi-breather solution differs slightly from the exact breather solution.Moving discrete breather interactions with the point defect in crystal with A₃B composition taken as an example Pt₃Al are studied by the method of molecular dynamics.

Zakharov P.V., Eremin A.M., Manakov N.A., Starostenkov M.D., Vdovin R.S.
COOPERATIVE ATOMIC DISPLACEMENTS NEAR INTERPHASE BOUNDARIES NI-γFE ^{[№ 6 ' 2016]}
By method of molecular dynamics studied the cooperative atomic displacements near the interface a bimetal solid-phase contact Ni-γFe. The differences in the behavior of the Ni and Fe atoms with their participation in the process of mass transfer across borders is established. Currently still a lot of unresolved issues related to the atomic structure of interfaces and mechanisms of their interaction with a variety of defects generated by, for example, by radiation exposure. In particular, special interest is the cooperative atomic displacements near the interphase boundaries and their contribution to the transport of energy and mass. It is shown that the introduction of interstitial atoms near the interface can cause a cooperative atomic displacements that lead to the climb of misfit dislocations. All cooperative atomic displacements proceeded on crowdions mechanism along the packed rows. The differences of behavior of atomic displacements on the number of interstitial atoms, and their type. The differences in the behavior of atoms, apparently, due to the high binding energy of the type Ni-γFe compared with connections type γFe-γFe, resulting in the Fe atoms are more mobile than the Ni atoms and penetrate through the interface is much more intense. Such activity of Fe atoms near the interface Ni-γFe border creates the preconditions for the consideration of such phenomena in the boundary as the basis for the creation of new materials with specific desired properties.

Zakharov P.V., Eremin A.M., Starostenkov M.D., Manakov N.A.
MOVING DISCRETE BREATHER INTERACTION WITH THE POINT DEFECT IN THE CRYSTAL WITH A₃B COMPOSITION ^{[№ 3 ' 2016]}
Moving discrete breather interactions with the point defect in crystal with A₃B composition taken as an example Pt₃Al are studied by the method of molecular dynamics. The problem of interaction the objects of soliton with topological defects in the crystal is important for assess the prospects of the use of such solitons, as discrete breathers, in technological processes. As a point defect interstitial Al atom is, placed into the tetrahedral cavity of the crystal. To make excitation of the moving discrete breather two Al atoms were deviated from their equilibrium position on the value of 0,5–1 A and 1 A to the opposite sides along the densely packed directions this way the initial velocity of the discrete brearher moving through the crystal. Moving discrete breather excitation is possible along the densely packed directions: <110>, <011>, <101>, <110>. In the chosen model several atoms of the light sublattice participate in the moving discrete breather oscillations.In this case moving discrete breathers can migrate through the crystal at a considerable distance, almost without dissipation its energy. The obtained data allow us to judge about moving discrete breather influence on the point defect in the crystal due to its speed, energy and the distance to the defect. This opens up a prospect of usage such objects as analyzer of alloy purity and defect structures in the crystals with A₃B composition. Moreover such objects can be used to transfer energy or information along the crystal.

Zakharov P.V., Eremin A.M., Manakov N.A., Starostenkov M.D., Markidonov A.V.
BEHAVIOR OF THE QUASI-BREATHER MODE IN PT₃AL CRYSTAL WITH THE POINT DEFECTS ^{[№ 9 ' 2015]}
Nowadays the localized oscillations of the atoms or separate atomic groups are being studied in the perfect chips what makes the usage of the acquired results more difficult when studying the real crystals with the deffects. In this researсh by the method of molecular dynamics we study influence of the point defects on the quasi-breather mode behavior in stoichiometry crystal A3B using Pt₃Al as an example. As point defects there are divacancies, trivacancies Pt in the crystal of Pt₃Al as well as interstitial atoms of Al that are placed into the tetrahedral vacuums. The considered model is a bulk stoichiometry crystal A₃B, where the atoms interact through Morse pair potential. It was found that point defects within Pt₃Al alloy substantially influence on the quasi-breather mode in the case of their close arrangement. The exposure is in the high-amplitude localized oscillations destruction with the further energy dispersion through the crystal. But it's worth to remark that while high-amplitude oscillations degradation dispersion predominantly takes place into Al sublattice where the energy stays localized because of the forbidden band availability in the phonon spectrum of Pt₃Al crystal during the long period of time. Besides it's established that there is a quasi-breather mode extended stability region near Pt divacancy and trivacancy. In the event of the observing at the point defect in the form of the interstitial Al atom, that is implantated into the tetrahedral vacuum such region does not exist. The acquired results should be counted while investigating the features and qualities of the real stoichiometry crystals А₃В.