M. N. Lubov

Kinetic model of growth of GaAs nanowires

A kinetic model of growth and formation of the crystal structure of gallium arsenide nanowires by molecular beam epitaxy on surfaces activated by Au drops is developed. The thicknesses of alternating layers of cubic and hexagonal phases formed due to fluctuations of the solution composition in the drop are calculated and compared with experimental data.

Study of Si and C adatoms and SiC clusters on the silicon surface by the molecular dynamics method

Individual Si and C adatoms, as well as SiC clusters, on a Si surface are simulated by the molecular dynamics method in the course of investigation of the initial stages of formation of a SiC layer on silicon with the help of molecular beam epitaxy. The potential energy surfaces for Si and C adatoms on the (2 × 1) reconstructed Si(001) surface and on the nonreconstructed Si(111) surface, as well as on the Si(111) surface with a SiC cluster, are calculated and analyzed. The values of migration barriers for adatoms on these surfaces are calculated. The effect of the SiC cluster on deformation of the surface region of Si(111) and on the migration of adatoms is investigated. The deep minima observed on the potential energy surfaces immediately above a cluster and at its boundaries can trap diffusing adatoms. The distributions of stresses and strains in the silicon lattice under a cluster on the surface are studied and described.

A kinetic model of amino-acid polymer growth in sodium and potassium aqueous solutions

A kinetic model was proposed and computing calculations of formation of short polymer chains (oligomers) from monomers (amino acids) in aqueous solutions with sodium and potassium ions for which energies of monomer addition to the chain were carried out. It is shown that formation of longer chains of monomers in potassium medium, in comparison with sodium medium, is caused by a smaller value of the energy of addition.

Computer simulation of the growth of GaAs nanowhiskers with inhomogeneous crystal structures

A physical model is proposed for the growth of GaAs nanowhiskers (NWs) with inhomogeneous crystal structures during the molecular beam epitaxy. Numerical calculations performed using this model give the temporal variation of the growth rate and the height of NWs and indicate the moments of switching from one crystal phase to another. The results of calculations coincide with the available experimental data.

Initial Stages of the MBE Growth of Silicon Carbide Nanoclusters on a Silicon Substrate

The growth of silicon carbide (SiC) nanoclusters by molecular beam epitaxy on silicon substrates has been studied using a combination of experimental and theoretical methods. The first results concerning the initial stages of this growth are presented.

Thermodynamic determination of the critical radii of surface and subsurface cobalt clusters in the cobalt-copper system

We have considered the thermodynamics of the formation of cobalt clusters on the surface of a copper substrate and in its subsurface region. Free energies of the formation of surface and subsurface clusters are calculated, and their critical radii are estimated.

Kinetic simulation of the 3D growth of subsurface impurity nanoclusters during cobalt deposition onto a copper surface

A physical model of the 3D growth of a subsurface cobalt cluster during the epitaxy of cobalt atoms on a copper substrate is developed. Time dependences are established for the cobalt cluster radius and height.

Kinetic modeling of the growth of copper clusters of various heights in subsurface layers of lead

The growth of subsurface copper clusters of various shapes and heights during the deposition of copper onto lead has been studied by kinetic modeling. The heights and radii of clusters have been calculated. Based on a comparison with experimental data, it is established that significant differences in the heights of clusters possessing different shapes are determined by the specific elastic energy of the copper cluster–lead interface.

Theoretical analysis of the formation of impurity precipitates in nanocavities I. Thermodynamic analysis

The formation of the impurity phase in materials containing nanopores is investigated theoretically. The formation of impurity clusters on the inner surface of pores is studied using the thermodynamic approach. The most advantageous states of metal impurities in silicon are determined, and comparison with available experimental data is carried out. The possibility of the formation of cobalt nanoclusters in subsurface cavities in copper is substantiated theoretically.

Molecular dynamics study of the diffusion barriers for silicon and carbon adatoms on a Si(111) surface

Barriers for the diffusion of silicon and carbon adatoms on an ideal (nonreconstructed) Si(111) surface and at silicon carbide (SiC) clusters of various sizes occurring on this surface have been determined using molecular dynamics simulations with a many-body Tersoff potential.