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Physics of the Solid State
Journal Prestige (SJR): 0.415

Citation Impact (citeScore): 1
Number of Followers: 3

Hybrid journal (It can contain Open Access articles)
ISSN (Print) 1090-6460 - ISSN (Online) 1063-7834
Published by Springer-Verlag

[2468 journals]

Influence of the Chemical Composition of Steel on the Structure and
Properties of Diffusion Coatings Obtained by Simultaneous Saturation of
Structural Steels with Boron, Chromium, and Titanium
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  Abstract: — The paper presents a comparative analysis of the microstructure of diffusion coatings on steels 45 and 38Kh2MYuA obtained by simultaneous diffusion saturation with boron, chromium and titanium. The saturation was performed by packing the saturable samples with sizes of 15 × 15 × 50 mm in a heat-resistant container with a powder saturating medium. At saturation of steel 45, the thickness of the diffusion layer is 120–140 µm, while at saturation of steel 38Kh2MYuA, the thickness of the diffusion coating is in the range of 70–80 µm, which is 58% less. The transition zone of the sample made of steel 38Kh2MYuA contains up to 20 vol % ferrite, while, in the case of steel 45, the transition zone is represented only by pearlite. The maximum microhardness of the diffusion layer on steel 38Kh2MYuA is 1.8 times lower than the indicator of the maximum microhardness of the diffusion layer on steel 45. At the same time, the surface microhardness on both steels is practically the same and is in the region of 1500 HV0.1. The microhardness of the transition zone in the case of steel 45 is higher than in the case of steel 38Kh2MYuA due to the almost complete absence of the ferrite phase. According to the data of durometric analysis, the thickness of the diffusion layer on steel 38Kh2MYuA does not exceed 85 μm, the thickness of the diffusion layer on steel 45 is 120 μm, which correlates with the results of metallographic analysis. Parts made of 38Kh2MYuA steel strengthened by complex boron–chromium–titanizing, having a lower surface hardness than parts made of steel 45, have high prospects for use as one of the parts that make up the friction pair of critical units. As the second part, it is possible to use boronized steel 45.
  PubDate: 2023-11-22
Influence of High-Temperature Annealing of Aluminum Alloys AMg6 and V95 on
Their Structural-Phase State and Strength Properties
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  Abstract: The widespread use of structural aluminum alloys AMg6 and V95 in modern mechanical engineering has led to the identification of such a problem as the non-optimal structure of commercial semi-finished products from these alloys. Traditional types of heat treatment do not always make it possible to correct the structure and obtain a high complex of operational properties. The most common structural defects in commercial semi-finished aluminum alloys containing magnesium and zinc are banding formed by the strengthening intermetallic phase MgZn2. The structure of magnesium–aluminum alloys has been studied by high-resolution optical microscopy under various heat treatment modes, which include long-term homogenization annealing. The studies were carried out on samples of AMg6 and V95 alloys. For heat treatment, a chamber furnace of the SNOL type equipped with a PID controller was used; the samples were loaded into a furnace preheated to a temperature of 500°C and kept in it for 8 and 16 h. After the exposure was completed, the samples were removed from the furnace and cooled in still air. The hardness was measured on the original samples, samples after heat treatment and 14 days after heat treatment. Studies have shown that an increase in the time of high-temperature holding at 500°C for both alloys leads to the dissolution of intermetallic particles. As a result of the ongoing structural-phase transformations during further cooling and subsequent natural aging, the intermetallic phase again precipitates from the solid solution, as shown by hardness measurements made on the original samples, then after high-temperature annealing and subsequently after natural aging for 14 days.
  PubDate: 2023-11-22
Molecular Dynamics Simulation of Reduction of the Surface Layer Porosity
in a BCC Crystal Induced by Laser Pulses
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  Abstract: A deeper understanding of the interaction of laser radiation with matter can facilitate the development of technologies for laser synthesis of materials with unique properties, nanostructuring of surfaces of processed solids, etc. The difficulties related to direct observations of various fast processes contribute to the progress in the computer simulation methods used to study them. This work presents the results of the simulation of reduction of the iron surface layer porosity induced by laser pulses. The investigations have been carried out using the potential calculated within the embedded atom method. The model under study has been subjected to structural analysis using the proven algorithms, which makes it possible to quantify the surface area of pores in the bulk of a crystal. The computational cells under consideration contain pores in the amorphous region, which remain stable upon the model cooling corresponding to the natural cooling of a solid in the environment described by a mathematical expression. Obviously, to get rid of defects, a solid should be annealed. It is shown that, after annealing at a temperature of no higher than half of the melting point, pores are preserved. Taking into account that the main mechanisms for reducing the porosity are the diffusion-viscous flow of matter into pores and that diffusion in the amorphous phase is more intense than in the crystalline one, the conditions for slowing down crystallization at a certain temperature should be established in the model. The required conditions have been achieved by straining the computational cell. It is shown that, as a result, the number of pores decreases under both compression and tension.
  PubDate: 2023-11-22
Mechanical and Thermal Properties of the Titanium Dioxide-Modified
Composites Based on Aluminum Hydroxide and a Polyethylene Mixture
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  Abstract: The results of investigations of the mechanical and thermal properties of the composites modified with a structure-forming agent based on aluminum hydroxide and a high- and low-density polyethylene blend are reported. The properties of the polymer composites, including the fracture stress, relative elongation, melt flow index, heat resistance, thermal stability, and thermomechanics, have been studied. All the composite materials have been based on a titanium dioxide-modified (1 wt %) high- and low-density polyethylene blend (50/50). The aluminum hydroxide content has been varied within 1‒30 wt %. Using the data obtained on the Kanavets device, the temperature dependences of the deformation have been built and the regularities of changes in the thermomechanical curves have been established. It has been shown that, in all the investigated samples, a transition from the solid to viscous-flow state occurs with increasing temperature. The thermal stability has been estimated by the thermogravimetric analysis.
  PubDate: 2023-11-22
Computational Modeling of a Robot with Hydraulic Control by Velocity
Vector Walking on a Solid Surface
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  Abstract: — The use of walking machines is topical for many engineering works in complex physical media and hydrological studies. To develop the controlling system of a walking machines, it is necessary to have a kinematic and dynamic models of such a machine. The aim of this work is to develop a kinematic model for an acting model of a six-legged walking solid-state robot that will allow us to obtain in computational experiments a visual representation of a machine motion in space when actuating a control algorithm. The mathematical description of the kinematic model is developed for a six-legged walking robot in the form of systems of equations that allow us to determine the position of the robot units at given rotation angles of limb links. The system of difference equations allowing modeling of the robot motion with velocity vector control is obtained. The model is used for imitation modeling of scenarios of various types of robot movements in the MATLAB software. The model takes into account the events leading to a change in the velocity mode. This computational model assumes that the robot limb angle is changed by a hydraulic actuator. The equations that determine the relation of the hydraulic rod extension and the limb angles are derived taking into account the peculiarities of the control algorithm. To estimate the possibilities of robot movement, the foot reach area is constructed and the analytical boundaries; of this area are found. This kinematic model is used when developing and approbating machine movement control algorithms and also to control the machine model in the servo drive mode. The development of the methods of modelling the hydraulically controlled robotics is proposed on the base of the modernization of the formal hierarchy of hybrid- time events in an extended form of the kinematic model on the base of a hybrid automatic with transitions.
  PubDate: 2023-07-10
  DOI: 10.1134/S1063783423010018
Accumulation of Defects under Plastic Deformation of Polycrystalline
Copper-Based Alloys
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  Abstract: The paper presents the experimental investigation of the role of the size factor in the formation of the defect structure of metallic materials. The objects of study were polycrystalline FCC Cu–Al and Cu–Mn solid solutions with average grain sizes of 10–240 µm. The dislocation structure of foil samples subjected to various deformations at room temperature was studied by TEM. We measured the scalar dislocation density (ρ), the density of geometrically necessary dislocations (GND) (ρg), the density of statistically stored dislocations (SSD) (ρs), the curvature-torsion of the crystal lattice (χ), and some other parameters. The effect of the grain size of the dislocation substructure on its parameters has been quantitatively studied. The sources of curvature-torsion χ of the crystal lattice were determined from electron microscopic images. We measured χ in the alloys under study from different sources and its change with distance (x) from the source for alloys with fixed grain size and degree of deformation. The change in the average value of curvature-torsion from all sources with the degree of deformation is considered.
  PubDate: 2023-03-02
  DOI: 10.1134/S1063783422110129
Specific Heat of CoFe2O4 and the 0.3CoFe2O4–0.7PbTiO3 Composite
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  Abstract: — The temperature dependence of the specific heat of the CoFe2O4 ferromagnet and the 0.3CoFe2O4–0.7PbTiO3 muliferroic composite is studied in the temperature range 150–820 K. An addition of lead titanate ferroelectric to cobalt ferrite ferromagnet is found to lead to a shift of the magnetic phase transition temperature to lower temperatures by 49 K and to a decrease in the specific heat in a wide temperature range. It is noted that the additional component of the specific heat is due to transitions of cobalt or iron ions to higher energy levels and also due to a distortion of the lattice parameters as a result of formation of three coexisting phases.
  PubDate: 2023-03-02
  DOI: 10.1134/S1063783422110075
Current Instability of Hardening of a Deformable Medium Element as a
Reason of the Neck Propagation
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  Abstract: The effect of the current instability of hardening of a deformable medium element on the strain localization at different scale levels has been studied. The current instability term has been taken from the characteristic of the current instability of the electrical conductivity of semiconductors in strong electric fields with a specific I‒V curve [1]. A similar shape of the σ‒ε curve of hardening of a deformable medium element has been considered to be the cause of the strain localization. The strain localization phenomena caused by the current instability of different types have been discussed and modeled. It is shown that the plastic flow scenario under the current instability at the level of a microelement of a medium can manifest itself at the macroscale plastic flow level in the form of localizations of various types. The simulation within a two-level finite element model proposed previously in [2] has been carried out. The cases of a stable neck or neck propagation at the macrolevel under the uniaxial tension of a sample have been observed, depending on the shape of the hardening curves of the unit volume of a deformed sample similar the current instability curves.
  PubDate: 2023-03-02
  DOI: 10.1134/S1063783422110117
Effect of the Thickness on the Resistivity of Thin Diamond-like Carbon
Coatings on Silicon Substrate
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  Abstract: The relationship between sp2/sp3 hybridizations ratio of atomic bonds in diamond-like carbon (DLC) and its electrical resistivity for coatings with a thickness in the range 22–70 nm prepared by vacuum arc deposition on silicon substrate of the SHB-8 brand has been established. It is established, that an increase in the coating thickness from 22 to 70 nm is accompanied by a decrease in the specific transverse electrical resistance of samples from 17 to 2 GΩ m. This effect is explained by an increase in the proportion of carbon atoms with sp2 hybridization of electronic orbitals from 86 to 91%, which leads to the appearance of an additional number of π-bonds. A mathematical model describing the spatial distribution of current when measuring the transverse I–V characteristic, has been developed. The results obtained will be useful in creating resistive layers on the electrodes of gas-discharge detectors of charged particle to limit the amount of c-urrent in the event of rare spark discharges inside them caused by the registration of random highly ionizing pa-rticles.
  PubDate: 2023-03-02
  DOI: 10.1134/S1063783422110166
Strengthening Mechanisms and Features of Strain Stages in High-Manganese
Austenitic Hadfield Steel
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  Abstract: — The paper presents the study of the deformation effect on high-manganese austenitic Hadfield steel. The dependences of the flow stress and the strain-hardening coefficient on the degree of plastic deformation in uniaxial tension revealed that the linear stage II of strain-hardening at ε ~ 5% can be divided into two substages different in the type of dislocation substructures and values of strain-hardening coefficients. The change in the strain-hardening coefficient correlates with the time when the twinning processes are switched on and the beginning of the transition of the dislocation substructure from one type to another. The following quantitative parameters were determined: the volume fraction of the material caught up by slip and twinning; the volume fractions of the material where twinning develops in one, two, and three systems. Twinning develops most intensively in the range of ε = 5–20%. The involvement of various types of defects (microtwins and dislocations) in the process of deformation does not depend on the method of plastic deformation (tension, rolling). The role of crystallographic texture, which manifests itself in an increase in the Schmid factor during the formation of microtwins, is determined, since microtwinning entails orientational softening and facilitates the sliding process. The presence of minimal and even zero values of the Schmid fa-ctor during twinning was revealed in individual grains. In these grains, the driving force of twinning is the internal stress fields, the occurrence of which is due to the incompatibility of the deformation of neighboring grains.
  PubDate: 2023-03-02
  DOI: 10.1134/S1063783422110099
Luminescent Properties of Yttrium–Scandium Phosphate Solid Solutions
Doped with Europium Ions
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  Abstract: The luminescent properties of Y1 – xScxPO4: 0.5 mol % Eu3+ (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1) solid solutions are studied at the excitation by the radiations of ultraviolet and vacuum-ultraviolet ranges. The disordering of the solid-solution crystal structure is shown to influence the structure of the Eu3+ luminescence spectra. The bandgap width is shown to nonlinearly depend on the solid solution composition. The model explaining this effect is proposed.
  PubDate: 2023-03-02
  DOI: 10.1134/S1063783422110130
Diffusion and Stress Interrelation in the Transition Zone between a
Particle and a Matrix in Composite Synthesis
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  Abstract: A model of interaction between a solid particle and a metal melt is presented. This model takes into account some possible mechanisms of stress occurrence in the transient zone, formed between the particle and the matrix during the composite synthesis. It is assumed in the examples that either only one new phase or only two new phases appear between the initial particle of the refractory component and the melt. The mechanical stresses accompanying diffusion and growth of the new phase result from the solution of equilibrium problems. Approximate analytical solutions of the coupled problems are given, including for the case where the explicit dependence of the diffusion coefficient on the stress is taken into account.
  PubDate: 2023-03-02
  DOI: 10.1134/S1063783422110063
Ab Initio Simulation of Dielectric and Optical Properties of Ices Ih and
III and Lattice Frameworks of Hydrates sI and sH
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  Abstract: In this study, the results of calculating the dielectric and optical characteristics of solid polymorphic phases of water—namely, ices Ih and III, and lattice frameworks of hydrates sI and sH—are described. Static dielectric tensors εik and complex frequency-dependent tensors εik(ω) are calculated for these materials. It is shown that the lattices of Ih, III, and sH correspond to uniaxial crystals according to their optical properties, their εxx(ω) and εyy(ω) tensor components are identical, and the lattice of hydrate sI corresponds to an isotropic crystal. Based on calculated frequency-dependent dielectric functions \({{\varepsilon }}_{{ik}}^{{\text{'}}}({{\omega }})\) and \({{\varepsilon }}_{{ik}}^{{{\text{''}}}}({{\omega }})\) , the following important optical characteristics are obtained: reflection R(ω), absorption a(ω), loss function L(ω), and refractive indices n(ω) and k(ω). Comparison of the dielectric and optical spectra of the sI and sH lattice frameworks with the known spectra for methane hydrate sI reveal a broadening of the spectra toward high-energy fields. For unfilled hydrate sI, a reflection peak at an energy of 17.3 eV is found, the appearance of which is associated with a change in the electronic structure of the crystal in the absence of a methane molecule. Qualitative agreement of reflection spectra R(ω) and the \({{\varepsilon }}_{{ik}}^{{\text{'}}}({{\omega }})\) and \({{\varepsilon }}_{{ik}}^{{{\text{''}}}}({{\omega }})\) functions calculated by quantum mechanical simulation with experimental data on the spectroscopy of the hexagonal and amorphous ice phases is obtained.
  PubDate: 2023-03-02
  DOI: 10.1134/S1063783422110142
Study of Domain Wall Dynamics in GdFeCo Using Double High-Speed
Photography
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  Abstract: It is shown using the technique of double high-speed photography that an external magnetic field triggers the motion of a GdFeCo domain wall with a velocity up to 1.2 km/s. The domain wall velocity increases and levels off with an increase in the amplitude of the driving magnetic-field pulse. In contrast to the earlier experiments on iron ferrites, no influence of femtosecond laser pulses on the domain wall dynamics has been observed, even when the pump pulse energy is sufficient for magnetization reversal.
  PubDate: 2023-03-02
  DOI: 10.1134/S1063783422110105
Diffusion of Phosphorus and Gallium from a Deposited Layer of Gallium
Phosphide into Silicon
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  Abstract: Diffusion from a layer of gallium phosphide GaP deposited onto a silicon surface is studied. After diffusion, the silicon samples are examined using the Van der Pauw method and a scanning electron microscopy in order to determine the concentration distribution of impurity atoms of phosphorus and gallium.
  PubDate: 2023-03-02
  DOI: 10.1134/S1063783422110154
Evaluation of the Mechanisms of Compression Hardening of Rail Steel
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  Abstract: Methods of modern physical materials science are used to study the evolution of structural-phase states and dislocation substructure of rail steel under uniaxial compression deformation up to 50%. The revealed fragmentation of pearlite grains becomes more expressed with increasing deformation, and the fragmentation of cementite plates with the fragment size of 15–20 nm weakly depends on the degree of deformation. The change in the scalar and excess dislocation density with increasing deformation is analyzed. Sources of internal stress fields are identified and classified. The data obtained formed the basis for a quantitative analysis of the mechanisms of hardening of rail steel at degrees of compression deformation of 15, 30, and 50%. The contributions to strengthening caused by friction of the matrix lattice, dislocation substructure, fragment boundaries, carbide particles, internal stress fields, solid-solution strengthening, and the pearlite component of the steel structure are estimated. The primary mechanism of metal hardening at the deformation of 50% is hardening by incoherent particles and elastic internal stress fields. Using the additivity principle, which assumes the independent action of each of the hardening mechanisms, the dependence of the total yield strength of rail steel on the degree of compressive deformation is estimated.
  PubDate: 2023-03-02
  DOI: 10.1134/S1063783422110087
Temperature Dependence of the Lattice Thermal Conductivity of Metastable
Phases of FCC Ti and Zr
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  Abstract: The metastable phases of a material have other, possibly anomalous properties as compared to its stable structural state. The elastic and dynamic properties of metastable phases with a face-centered cubic (FCC) lattice of highly anharmonic transition metals, Ti and Zr, calculated previously by the molecular dynamics method with many-body potentials, constructed using the embedded-atom method, are in good agreement with previous theoretical calculations. The possibility of using the non-equilibrium molecular dynamics method to calculate the lattice thermal conductivity of metastable FCC structures in both metals is demonstrated. Temperature dependences of the lattice thermal conductivity coefficients of FCC Ti and Zr are obtained for crystallites with a cross section of 12 × 12 FCC unit cells (u.c.) and lengths of 48 and 96 u.c. The results are compared with the previously calculated lattice thermal conductivity of Al, which is consistent with ab initio calculations.
  PubDate: 2023-02-10
  DOI: 10.1134/S1063783422100018
Transport Properties of Layered Heterostructures on the Base of a
Conducting Polymer
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  Abstract: Polydiphenilenphtalide (PDP) belongs to organic dielectrics that demonstrate the electroconducting properties, when applying an external electrostatic field and/or mechanical stresses. In this work, the transport characteristics of thin-film lead–PDP–lead layered structures are studied in a wide temperature range. At quite high temperatures, current–voltage characteristics are adequately described in terms of the injection current model confirmed by a space charge. At temperatures below ~7.5 K, a number of the sample demonstrate peculiarities that can be explained by the effect of induced superconductivity in a thin film of a conducting polymer included between two massive superconductors (lead).
  PubDate: 2022-12-01
  DOI: 10.1134/S1063783422120010
Kinetics of Convergence the Si(100) Surface Steps
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  Abstract: The convergence kinetics of SA and SB steps on Si(100) substrates with inclination of 0.5° and 0.1° are studied. To establish the character of the growth kinetics, the time dependences of the reflection high‑energy electron diffraction (RHEED) intensity are analyzed. It is shown that the convergence rate of the steps in the Si at a growth rate of 0.37 ML/s has a decreasing dependence with an increase temperature. It is found that the rate of formation of a single-domain surface increases with the width of terraces on the surface, which is likely to be related to a partial participation of the growth due to the formation of two-dimensional islands. At temperatures higher 650°С, the dominant growth mode due to the motion of the steps and the rate of formation of the single-domain surface decrease with an increase in the terrace width. Thus, the convergence of single-layer steps is determined by the conditions of the growth of the molecular-beam epitaxy (MBE) and also by the Si(100) substrate orientation. The convergence of SA and SB steps of the Si(100) surface is explained by a slow-down motion of SA which is related to complex mechanisms of permeability and the formation of step kinks. It is assumed that the cause of the slow-down convergence the steps with increasing temperature is an increase in the kink density on the SA step, which decreases the permeability coefficient of the SA step.
  PubDate: 2022-12-01
  DOI: 10.1134/S1063783422120022
Conduction Mechanisms and Thermoelectric Properties of Semimetallic CaSi
and CaSi2 Films on Si(100) and Si(111) Substrates
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  Abstract: Nanocrystalline CaSi films with thicknesses from 80 to 130 nm were grown on high-resistance silicon substrates with orientations (111) and (100) by the methods of low-temperature (190–330°C) molecular-beam epitaxy and low-temperature (330°C) solid-phase epitaxy, for which the microstructure, phase composition, and crystal structures were studied. It is found that the polycrystalline, nanocrystalline (NC), and amorphous CaSi and CaSi2 films are characterized by preferential contribution of holes in the range 1.4–300 K. In magnetic fields 1–4 T and at temperatures 40–100 K, a giant linear magnetoresistive effect (MRE) (to 500%) was observed for the first time in CaSi films with the contribution of another CaSi2 phase. In CaSi2 film containing another phase (CaSi), peaks are detected on the temperature dependences of the resistivity and the Hall coefficient that correspond to a phase transition. In addition, in this film, the transition from the positive MRE to negative MRE is observed at Т = 120–200 K. This effect is not observed in the single-phase CaSi2 film, which corresponds to a certain reconstruction of carrier flows in a magnetic field only in the two-phase system. The study of the thermoelectric properties of CaSi and CaSi2 films shows that the semimetallic type of the conduction in them leads to the independence of the positive Seebeck coefficient Т = 330–450 K. It is found that the maximum contribution to the Seebeck coefficient and the power factor are observed in the amorphous CaSi film in the case of the presence of some fraction of NC Ca2Si phase. In the single-phase CaSi2 films, the Seebeck coefficient and the power factor are halved due to an increase in the hole concentration as compared to the CaSi films.
  PubDate: 2022-12-01
  DOI: 10.1134/S1063783422120034