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A. Yu. Zakharov

Publications and source records attributed to A. Yu. Zakharov.

27 records · Page 2Linked to original sources
arXiv2013

Exactly solvable model of the ferroelectrics hysteresis loops control by the external electric field

The kinetic theory of switching processes in crystalline ferroelectric materials under the influence of a variable external electric field is formulated. The basic equations are derived and their exact analytical solution at arbitrary time-dependent external field are obtained. Connection between the hysteresis loops shape and variable external electric field parameters is investigated numerically. The numerical results were found to be in excellent agreement with the experiments. PACS: 77.80.Fm, 77.80.Dj, 77.80.-e Keywords: ferroelectrics, switching processes, hysteresis curves, polarization

cond-mat.mtrl-sci↗
arXiv2011

Exactly solvable model of uniaxial ferroelectrics

An exactly solvable lattice model with infinite-range potential is applied to uniaxial ferroelectrics. Asymptotically exact expression for free energy as a function of an order parameter at any temperatures is obtained. Effect of thermal expansion of lattice unit cell is taken into account. The free energy expansion in powers of order parameter in the vicinity of critical point is presented. Corrections to Landau expansion are obtained. In particular, it is shown that summand with external field contains a contribution of higher powers over order parameter. Keywords: Lattice model, Free energy, Phase transition, Long-range interatomic potentials, Curie temperature, polarization PACS: 05.20.-y, 05.70.-a, 82.65.+r

cond-mat.mtrl-sci↗
arXiv2011

A fast algorithm of coexisting phases compositions calculation in binary systems

A simple fast algorithm of the conodes calculation in binary systems is proposed. The method is based on exact solution of the problem on common tangent to pair of approximating parabolas. Sequence of approximating parabolas pairs having second order tangency points on separated concave parts of free energy isotherm is generated. The sequences of the tangency points pairs conodes with approximating parabolas converge to equilibrium compositions of phases in binary systems. PACS: 64.75.-g; 64.10.+h; 05.70.Ce; 82.60.-s Key words: Phase equilibria; Free energy; Binary systems; Conode; Phase diagrams.

cond-mat.stat-mech↗
arXiv2010

On the theory of ferroelectric solid solutions

The paper contains an application of lattice model to ferroelectric solid solutions. Short-range parts of interatomic potentials are taken into account by means the lattice structure introduction. Long-range parts are considered in effective field approximation. The equations for the mean values of the components contributions into polarization are derived. The general equation for the Curie temperature dependence on solution composition is obtained. Theoretical calculation of Curie temperature of the system Pb$_{1-x}$Sn$_x$TiO$_3$ fulfilled.

cond-mat.mtrl-sci↗
arXiv2010

Selected aspects of the condensed matter physics. Work and life of Professor B.Ya. Sukharevsky

The paper contains a short description of the scientific papers of Professor Boris Ya. Sukharevsky on condensed matter physics. His basic scientific activity was related to following directions: structural vacancies concept; influence of point defects on statics and kinetics of phase transitions; DNA crystallization and low-dimensional systems properties; phase transitions in Jahn-Teller crystals; Thermophysics of superconductors e.a. The list of most essential papers of Prof. B.Ya. Sukharevsky is included.

cond-mat.mtrl-sci↗
arXiv2010

Variable-lattice model of multi-component systems. 1. General consideration

The paper contains a development of the previously proposed generalized lattice model (GLM). In contrast to usual lattice models, the difference of the specific atomic volumes of the components is taken in account in GLM. In addition to GLM, the dependence of the specific atomic volumes on local atomic environments taken into account in new variable-lattice model (VLM). Thermodynamic functions of multi-component homogeneous phases in the VLM are obtained. Equations of equilibrium between gaseous and condensed phases are derived. PACS: 05.20.-y, 05.70.-a, 82.65.+r Key Words: Lattice models, Free energy, Phase equilibrium, Long-range and short-range inter-atomic potentials

cond-mat.stat-mech↗
arXiv2009

Generalized Lattice Model of Multi-Component Systems with Internal Degrees of Freedom. II. Quasiequilibrium States

The paper contains an application of the generalized lattice model to multicomponent systems with internal degrees of freedom. The short-range inter-atomic repulsions and smooth long-range parts of the inter-atomic potentials are considered separately by means of packing condition and in effective field approximation, respectively. The dependence of the inter-atomic potentials on the internal degrees of freedoms (such as atomic electric and/or magnetic momentum) taken into account. The Helmholtz free energy functional in the generalized lattice model is reduced to the Ginzburg-Landau-Cahn-Hilliard-like form. The connection between the inter-atomic potentials characteristics and the parameters of the GLCH-like functional is obtained. Equations for both equilibrium and quasi-equilibrium states in condensed systems are derived. It is shown that equilibrium distribution of the fast internal degrees of freedom by frozen space distribution of the components obeys to the Schroedinger-like equation.

cond-mat.stat-mech↗
arXiv2008

Generalized Lattice Model of Multi-Component Systems with Internal Degrees of Freedom. I. General consideration

The paper contains the generalization of usual lattice model of multicomponent systems. The generalization is related to account the following factors: 1. The short-range parts of interatomic repulsions. These repulsions are not identical for different pairs of atoms, therefore it is impossible to take into account the repulsions by means of usual ideal lattice introduction. 2. The long-range interatomic potentials take into account by means of effective fields approximation. 3. The presence the interatomic potentials depending on some inner degrees of freedoms such as atomic electric and/or magnetic momentum. The Helmholtz free energy functional in the generalized lattice model is reduced to the Ginzburg-Landau-Cahn-Hilliard-like (GLCH) form. The connection between the interatomic potentials characteristics and the parameters of the GLCH-like functional is obtained. The equations for both full and partial equilibrium distributions of the species in multicomponent systems are derived.

cond-mat.stat-mech↗