I. F. Golovnev

Defect generation as a phenomenon of structure self-organization under external loads

The generation of defects as a phenomenon of structure self-organization under the action of an external energy flux was investigated on an example of compression of a solid nanostructure. It is shown that there exists a critical energy flux at which the system experiences an avalanche change both in the time- and load-dependence of energy absorption and in the type of wave processes in its structure.

Molecular dynamics study into the role of the surface in fracture of nanostructures

The paper reports on a molecular dynamics study of fracture of ideal nanostructures and processes occurring in the surface and bulk atomic systems. It is shown from the first principles that fracture begins in the surface layer and then a crack is generated in the bulk.

Molecular dynamics study of cluster structure and rotational wave properties in solid-state nanostructures

Molecular dynamics simulation was performed to study the formation of cluster structure, interfaces, and surfaces with different curvature radii in a perfect nanocrystal passed through by a nonlinear wave. It is shown that this process is a type of nanostructure self-organization in response to an external energy flux with subsequent development of a strong rotational field.

Structure of zirconium tetrahydroborate Zr(BH4)4: A molecular dynamics study

In the work the structural and thermodynamic characteristics of zirconium tetrahydroborate Zr(BH4)4 are considered. The initial compound organized in a cubic lattice was heated from absolute zero to temperatures exceeding the experimental boiling temperature. Temperature dependences of the parameters of the internal structure, energy, and density of molecules in bulk are obtained. It is found that on heating the compound to 300 K its structure is maintained and on further cooling it returns to the initial state. On heating above 400 K the irreversible destruction of the crystal lattice is observed. On further cooling the compound in the solid phase becomes amorphous. It is shown that in the new state the average binding energy is lower than that in the initial one and the cubic lattice has the highest binding energy among the considered Zr(BH4)4 structures.

Molecular-dynamical study of surface tension in nanostructures

AbstractIn the present paper, we perform a molecular-dynamical study of the surface tension in nanodimensional structures. In this case, we find three types of surface characteristics corresponding to different mechanisms of the surface reaction to the external actions: 1.Compression of clusters by the system of surface atoms in the absence of external actions (the Laplace pressure) and the dependence of the internal pressure on the radius.2.Reaction of the already compressed cluster to the additional external compressive or expansive pressure, which results in surface deformation and in variations both in the energy of the surface atoms and in the binding energy of the surface and the bulk atoms.3.Energy necessary to form a new surface under unloading (the Griffith energy).

Effect of Nanostructure Size on Parameters of Rotational Fields Induced by External Compressive Stress

This paper continues a series of studies on the formation and development of vortex structures in solids using the molecular dynamics method. This phenomenon is interpreted from the viewpoint of structural self-organization. The effect of the structure size on the formation of rotational fields has been studied to show that their appearance is not a consequence of the specimen nanosize. It is shown that the lateral nanostructure size influences the rotational field energy.

Generation of rotational fields due to thermal motion of atoms in metals

Molecular dynamics investigation is performed on rotational fields in an isolated nanosized metal crystal at a certain temperature. Such fields are shown to exist even without external mechanical action. We investigate how the temperature and size of nanostructures affect specific rotational energies of atom subsystems. Statistical processing of the numerical data is used to find the dependence of the specific rotational energy of atoms on the structure temperature and size.

Molecular dynamics analysis of the substrate temperature effect on thermomechanical characteristics of vapor deposited nanofilms

Modern engineering applications are in need for technologies of nanostructures and nanofilms with controllable properties. The detection of these structures requires methods of atomic research, among which are molecular dynamics techniques, Monte-Carlo simulation, and ab initio calculation. The most efficient method to deal with systems of about several thousands of atoms is molecular dynamics simulation. We used this method to analyze the formation of nanolayers on a Cu substrate in vapor deposition of Cu atoms. It is shown that the film deposited on the substrate surface replicates the crystalline structure of the substrate. It is found that at low deposition temperatures, the deposited layer reveals a great quantity of vacancies and vacancy clusters (nanopores). It is demonstrated that increasing the substrate temperature in metal vapor deposition ensures a more perfect lattice in the nanocoating, and the cohesive energy of atoms in the nanolayer thus approximates experimental values. It is also found that the increase in substrate temperature in the process causes Young’s modulus and elastic limit to tend to the values of a perfect crystal.

The Investigation of Nano‐dimensional Alloys Thermodynamic Properties

The question on the nanothermodynamics creation haven’t solved in the science. In this connection this paper is devoted to the investigation of thermodynamics properties of nano length scale materials. In particular it is presented the results of calculation of thermodynamical properties of pure copper and its alloy with silver. It is taken the main magnitudes, allowing to get the state equation of nanostructures. And the chief result of the work is the development of the way of research of thermodynamical properties of nanostructure and the way of getting the state equation.

Molecular Dynamic Simulation of Detonation Phenomena

In the present study, the molecular dynamics method has been used to examine the influence of the thermal effect of the chemical reaction on processes in a detonating molecular crystal. Molecular dynamics data are compared with predictions of the continuum theory of detonation; in particular, fulfillment of the Chapman‐Jouguet condition is verified.