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Yuri Kornyushin

Publications and source records attributed to Yuri Kornyushin.

At least 19 recordsLinked to original sources
arXiv2013

Clausius-Mossotti approximation in the theory of polar materials

Clausius-Mossotti approximation is extended to describe the measured magnetic moment of an ellipsoidal sample containing magnetic or nonmagnetic ellipsoidal inclusions and magnetic or nonmagnetic matrix. The magnetic field in the matrix and inclusions is calculated. The magnetic energy of a system is calculated also. The equilibrium shape of a pore in a ferromagnetic sample is investigated. The phenomenon of cavitation in porous ferromagnetic samples is described. The model is applied to calculate magnetic properties of granular superconductors. The effective electric conductivity of a sample of a composite material, containing an arbitrary number of differently ordered distributions of ellipsoidal inclusions is calculated. Effective conductivity of a composite material, consisting of fibers of high conductivity and a matrix of low conductivity is discussed. Concentrated electric field in the vicinity of the ends of a conductive nanofiber in a composite material is calculated. The high quantity of this field is of an extreme importance to provide the proper functioning of monitors, based on conductive nanofibers in dielectric media.

cond-mat.mtrl-sci↗
arXiv2013

Application of Thomas-Fermi model to a negative hydrogen ion in a strong electric field

Thomas-Fermi model is applied to describe some basic properties of a negative hydrogen ion in a strong electric field. The equilibrium ionic size, energy and polarizability of the ion are calculated. Collective modes of the dipole oscillations are regarded. A barrier, due to which the ion is in a stable state, is studied. The barrier vanishes at some large value of the electric field, which is defined as a critical value. The dependence of the critical field on frequency is studied. At high frequencies a stripping mechanism for instability arises. At the resonant frequency comparatively low amplitude of the electric field causes the stripping instability.

cond-mat.mtrl-sci↗
arXiv2012

Some problems of low-dimensional physics

Fermi and kinetic energy are usually calculated in periodic boundary conditions model, which is not self-consistent for low-dimensional problems, where particles are confined. Thus for confined particles the potential box model was used self-consistently to calculate Fermi and kinetic energies in 3-, 2-, and 1-dimensional cases. This approach is much more logical and self-consistent. Then the conditions for neglecting dimensions, that is conditions under which the movement of particles in the box could be considered as 2- and 1- dimensional, were derived.

cond-mat.mtrl-sci↗
arXiv2012

Atmospheric instability as a loss of a metastable equilibrium

General thermodynamic theory of metastable states is used in this short note to try to understand better atmospheric instabilities. It is shown that not only cooling of a cloud can lead to rain, but heating also, especially when there are charged water drops in a cloud (in this case we have rain with lightning). The influence of the global warming on weather is discussed.

physics.ao-ph↗
arXiv2011

Electric Field in Materials, Containing Conductive Nanofibers

Concentrated electric field and its energy in materials, containing nanofibers, are discussed. It is shown that the electric field in the vicinity of the end of a fiber is proportional to the external applied field and to the fiber length, whilst it is inversely proportional to the fiber diameter. Specific electrostatic energy of a fiber in a sample under the action of external applied field is calculated. This energy appears to be negative and proportional to the ratio of the fiber length to its diameter. This means that longer fibers are more stable than the shorter ones.

cond-mat.mtrl-sci↗
arXiv2010

On the stability of a very dense deuterium-tritium plasma ball

General conditions of stability of a very dense deuterium-tritium plasma ball are discussed. It is shown that the decrease in the size of a plasma ball (increase in the plasma density) can be expected only when the temperature and the pressure in the plasma ball are kept high enough for all the particles, the nuclei and the delocalized electrons, to be described by classical statistics.

physics.plasm-ph↗
arXiv2010

Quantum rotator: some examples in modern spirit

Rotation of the nucleus and rotation of the electronic cloud of the atom/ion were considered. It was shown that these rotations are not practically possible. Rotation of the cloud of delocalized electrons and ionic core of a fullerene molecule and these of the ring of a nanotube were discussed. It was shown that the rotation of the cloud of delocalized electrons of a fullerene molecule is possible and it goes in a quantum way when temperature is essentially lower than 40 K. Rotation of the ion core of a fullerene molecule is possible in a classical way only. The same should be said about rotations in the ring of a nanotube.

physics.chem-ph↗
arXiv2009

On the effective conductivity of composite materials

A composite conductive material, which consists of fibers of a high conductivity in a matrix of low conductivity, is discussed. The effective conductivity of the system considered is calculated in Clausius-Mossotti approximation. Obtained relationships can be used to calculate the conductivity of a matrix, using experimentally measured parameters. Electric fields in the matrix and the inclusions are calculated. It is shown that the field in a low-conductivity matrix can be much higher than the external applied one.

cond-mat.mtrl-sci↗
arXiv2009

Kinetic and electrostatic energies in quantum mechanics

A concept of kinetic energy in quantum mechanics is analyzed. Kinetic energy is a non-zero positive value in many cases of bound states, when a wave function is a real-valued one and there are no visible motion and flux. This can be understood, using expansion of the wave function into Fourier integral, that is, on the basis of virtual plane waves. The ground state energy of a hydrogen atom is calculated in a special way, regarding explicitly all the terms of electrostatic and kinetic energies. The correct values of the ground state energy and the radius of decay are achieved only when the electrostatic energies of the electron and the proton (self-energies) are not taken into account. This proves again that self-action should be excluded in quantum mechanics. A model of a spherical ball with uniformly distributed charge of particles is considered. It is shown that for a neutral ball (with compensated electric charge) the electrostatic energy is a non-zero negative value in this model. This occurs because the self-energy of the constituting particles should be subtracted. So it shown that the energy of the electric field does not have to be of a positive value in any imaginable problem.

physics.chem-ph↗
arXiv2009

On the energy of electric field in hydrogen atom

It is shown that hydrogen atom is a unique object in physics having negative energy of electric field, which is present in the atom. This refers also to some hydrogen-type atoms: hydrogen anti-atom, atom composed of proton and antiproton, and positronium.

physics.gen-ph↗
arXiv2008

Semiclassical approach to the description of the basic properties of nanoobjects

Present paper is a review of results, obtained in the framework of semiclassical approach in nanophysics. Semiclassical description, based on Electrostatics and Thomas-Fermi model was applied to calculate dimensions of the electronic shell of a fullerene molecule and a carbon nanotube. This simplified approach yields surprisingly accurate results in some cases. Semiclassical approach provides rather good description of the dimensions of the electronic shell of a fullerene molecule. Two types of dipole oscillations in a fullerene molecule were considered and their frequencies were calculated. Similar calculations were performed for a carbon nanotube also. These results look rather reasonable. Three types of dipole oscillations in carbon nanotube were considered and their frequencies were calculated. Frequencies of the longitudinal collective oscillations of delocalized electrons in carbon peapod were calculated as well. Metallic cluster was modeled as a spherical ball. It was shown that metallic cluster is stable; its bulk modulus and the frequency of the dipole oscillation of the electronic shell relative to the ions were calculated.

cond-mat.mtrl-sci↗
arXiv2008

Understanding Kinetic Energy paradox in Quantum Mechanics

A concept of Kinetic Energy in Quantum Mechanics is analyzed. Kinetic Energy is not zero in many cases where there are no motion and flux. This paradox can be understood, using expansion of the wave function in Fourier integral, that is on the basis of virtual plane waves.

physics.chem-ph↗
arXiv2008

Thomas-Fermi model yields condensed phase of molecular metallic oxygen

Calculations, performed in Thomas-Fermi approximation, show that the energy of a condensed phase of molecular metallic oxygen is lower by 496 kJ/mol than that of an insulator oxygen phase. The insulator phase is separated from a metallic one by energetic barrier of 1165 kJ/mol. This barrier could be overcome by means of electromagnetic irradiation with quantum energy of 12.071 eV or a bit higher. During such a transition the amount of energy equal to 496 kJ/mol is released. It should be extracted from a sample to secure the existence of a metallic phase.

cond-mat.mtrl-sci↗
arXiv2007

Oxygen molecular plasma at ambient temperature and elevated or high pressure

Usually microscopic electrostatic field around ions is neglected when the ionization energy is concerned. The ionization energy is considered to be equal to that of a separate atom (molecule). Here the energy of the electrostatic field around ions is taken into account. It is shown that the energy of this field contributes to decrease in the effective ionization energy. The effective ionization energy may turn to zero at some critical concentration of delocalized electrons. This leads to a complete ionization of the atoms (molecules). Concrete calculations were performed for oxygen molecular gas.

physics.plasm-ph↗
arXiv2007

Screening and impurity ionization energy in semiconductors

Usually microscopic electrostatic field around charged impurity ions is neglected when the ionization energy is concerned. The ionization energy is considered to be equal to that of a lonely impurity atom. Here the energy of the electrostatic field around charged impurity ions in semiconductor is taken into account. It is shown that the energy of this field contributes to decrease in the effective ionization energy. At high enough current carriers concentration the effective ionization energy becomes zero.

cond-mat.mtrl-sci↗
arXiv2007

Alternative approach to the description of metallic clusters

A detailed simple model is applied to study a metallic cluster. It is assumed that the ions and delocalized electrons are distributed randomly throughout the cluster. The delocalized electrons are assumed to be degenerate. A spherical ball models the shape of a cluster. The energy of the microscopic electrostatic field around the ions is taken into account and calculated. It is shown in the framework of the model that the cluster is stable. Equilibrium radius of a ball and the energy of the equilibrium cluster are calculated. Bulk modulus of a cluster is calculated also.

cond-mat.mtrl-sci↗
arXiv2007

Application of Thomas-Fermi model to fullerene molecule and nanotube

Semiclassical description, based on electrostatics and Thomas-Fermi model is applied here to calculate dimensions of the electronic shell of a fullerene molecule and a nanotube. The internal radius of the electronic shell of a fullerene molecule, calculated within the framework of the model is 0.2808 nm. The external radius is 0.4182 nm. The experimental values are 0.279 nm and 0.429 nm correspondingly. This shows that semiclassical approach provides rather good description of the dimensions of the electronic shell in a fullerene molecule. Two types of dipole oscillations in a fullerene molecule are considered and their frequencies are calculated. Similar calculations are performed for a nanotube also. For a nanotube with a radius of the cylinder of the ions, Rn = 0.7 nm, the internal radius of the electronic shell, calculated within the framework of the model is 0.577 nm. The external radius is 0.816 nm. Three types of dipole oscillations in nanotube are considered and their frequencies are calculated.

cond-mat.mtrl-sci↗