Pub Date : 2024-05-07DOI: 10.1134/s1027451024020022
I. V. Amirkhanov, I. Sarkhadov, Z. K. Tukhliev, H. Gafurov
Abstract
Previously, numerical simulations of laser ablation of materials occurring under the action of ultrashort laser pulses in semiconfined samples and samples of finite thickness were carried out. Its thermal mechanism was described in terms of a one-dimensional unsteady heat equation in a coordinate system associated with a moving evaporation front. The action of the laser was taken into account through the source functions in the thermal conductivity equation, specifying the coordinate and time dependences of the laser source. In this work, similar simulations were carried out for semiconfined samples within the framework of a two-temperature thermal spike model, which consisted of two interrelated thermal conductivity equations for the electron gas and the crystal lattice. For the convenience of numerical simulation, in the equations of the thermal spike model, a transition was made to the coordinate system associated with the moving evaporation front of the material. Using numerical simulation, temperature profiles of the electron gas and crystal lattice at different times were obtained, and the dynamics of the temperatures of the electron gas and crystal lattice on the surface of the sample were calculated within the thermal spike model, taking into account the evaporation of the crystal lattice and the emission of electron gas from the surface of the sample. A comparative analysis of the numerical results obtained within both models was carried out.
{"title":"Simulation of Laser Ablation of Materials within the Thermal Spike Model","authors":"I. V. Amirkhanov, I. Sarkhadov, Z. K. Tukhliev, H. Gafurov","doi":"10.1134/s1027451024020022","DOIUrl":"https://doi.org/10.1134/s1027451024020022","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Previously, numerical simulations of laser ablation of materials occurring under the action of ultrashort laser pulses in semiconfined samples and samples of finite thickness were carried out. Its thermal mechanism was described in terms of a one-dimensional unsteady heat equation in a coordinate system associated with a moving evaporation front. The action of the laser was taken into account through the source functions in the thermal conductivity equation, specifying the coordinate and time dependences of the laser source. In this work, similar simulations were carried out for semiconfined samples within the framework of a two-temperature thermal spike model, which consisted of two interrelated thermal conductivity equations for the electron gas and the crystal lattice. For the convenience of numerical simulation, in the equations of the thermal spike model, a transition was made to the coordinate system associated with the moving evaporation front of the material. Using numerical simulation, temperature profiles of the electron gas and crystal lattice at different times were obtained, and the dynamics of the temperatures of the electron gas and crystal lattice on the surface of the sample were calculated within the thermal spike model, taking into account the evaporation of the crystal lattice and the emission of electron gas from the surface of the sample. A comparative analysis of the numerical results obtained within both models was carried out.</p>","PeriodicalId":671,"journal":{"name":"Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140883721","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-07DOI: 10.1134/s102745102402023x
D. V. Andreev
Abstract
It is shown that when a MOS (metal–oxide–semiconductor) structure is simultaneously exposed to radiation and the high-field injection of electrons, part of the radiation-induced positive charge can be suppressed when interacting with injected electrons, and the density of surface states can increase. These phenomena must be taken into account during the operation of MOS radiation sensors in high-field charge injection modes. High-field injection modes used for postradiation suppression of positive charge in MOS sensors are analyzed. It is established that to annihilate one hole (radiation-induced positive charge), it is necessary to inject (0.5–2) × 104 electrons into the gate dielectric; the magnitude of the electric field has almost no effect on the process of suppression of the radiation-induced charge.
摘要 研究表明，当 MOS（金属氧化物半导体）结构同时暴露于辐射和高场注入电子时，部分辐射诱导的正电荷会在与注入电子相互作用时被抑制，表面态密度也会增加。在高场电荷注入模式下运行 MOS 辐射传感器时，必须考虑到这些现象。本文分析了用于 MOS 传感器正电荷辐照后抑制的高场注入模式。结果表明，要湮灭一个空穴（辐射诱导的正电荷），需要向栅极电介质注入 (0.5-2) × 104 个电子；电场的大小对辐射诱导电荷的抑制过程几乎没有影响。
{"title":"Accumulation and Suppression of Radiation-Induced Charge in MOS Structures","authors":"D. V. Andreev","doi":"10.1134/s102745102402023x","DOIUrl":"https://doi.org/10.1134/s102745102402023x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>It is shown that when a MOS (metal–oxide–semiconductor) structure is simultaneously exposed to radiation and the high-field injection of electrons, part of the radiation-induced positive charge can be suppressed when interacting with injected electrons, and the density of surface states can increase. These phenomena must be taken into account during the operation of MOS radiation sensors in high-field charge injection modes. High-field injection modes used for postradiation suppression of positive charge in MOS sensors are analyzed. It is established that to annihilate one hole (radiation-induced positive charge), it is necessary to inject (0.5–2) × 10<sup>4</sup> electrons into the gate dielectric; the magnitude of the electric field has almost no effect on the process of suppression of the radiation-induced charge.</p>","PeriodicalId":671,"journal":{"name":"Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140883826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-07DOI: 10.1134/s1027451024020125
N. N. Mikheev, I. Zh. Bezbakh
Abstract—
The results of applying the statistics of a discrete multiple scattering process to analytically describe the dependence of the charge state of light ions in matter on particle velocity are presented. It is shown that the use of a technique based on taking into account the dependence of the charge state of the beam ions on the ratio of the ion velocity to the minimum velocity of the electrons of the substance makes it possible to calculate the stopping power of the substance for lithium, beryllium, boron, and carbon ions of medium and low energies corresponding to the experimental results.
{"title":"Dependence of the Charge State of a Light Ion Beam in Matter on Particle Velocity","authors":"N. N. Mikheev, I. Zh. Bezbakh","doi":"10.1134/s1027451024020125","DOIUrl":"https://doi.org/10.1134/s1027451024020125","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">\u0000<b>Abstract</b>—</h3><p>The results of applying the statistics of a discrete multiple scattering process to analytically describe the dependence of the charge state of light ions in matter on particle velocity are presented. It is shown that the use of a technique based on taking into account the dependence of the charge state of the beam ions on the ratio of the ion velocity to the minimum velocity of the electrons of the substance makes it possible to calculate the stopping power of the substance for lithium, beryllium, boron, and carbon ions of medium and low energies corresponding to the experimental results.</p>","PeriodicalId":671,"journal":{"name":"Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140883718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-07DOI: 10.1134/s1027451024020320
E. A. Koptelov
Abstract
This paper is an overview of the results obtained by a collaborative team of researchers from the Institute for Nuclear Research, Russian Academy of Sciences (INR RAS), and State Scientific Center of the Russian Federation—Institute of Physics and Power Engineering (SSC RF—IPPE) using the SVZ-100 lead slowing-down neutron spectrometer. The study focuses on measuring the fission cross sections of americium isotopes 241Am, 242mAm, and 243Am when bombarded by neutrons with energies below 100 keV. The high efficiency of the SVZ-100, facilitated by its substantial working-substance mass (100 t of high-purity lead) and neutron generation through proton irradiation with a 209-MeV accelerator at the INR RAS, enables the investigation of neutron-nuclear processes in microgram samples of radioactive nuclides, which is unattainable in experiments using time-of-flight spectrometry. Unique scientific information is acquired through lead slowing-down neutron spectrometry by collaborative research efforts at the INR RAS and SSC RF—IPPE. This information partially fills gaps or complements existing but often contradictory or insufficient data from experiments conducted on both time-of-flight installations and lead slowing-down neutron spectrometers at other research centers. The results of collaboration of the INR RAS and SSC RF—IPPE are documented in international nuclear data repositories, indicating, in several instances, the need for adjustments to recommended approximating and calculated values. Information is given on some implemented and planned studies on neutron fission cross sections of americium isotopes at other centers following completion of the collaboration of the INR RAS and SSC RF—IPPE.
{"title":"Lead Slowing-Down Neutron Spectrometry 1: Cross-Section Data for 241Am(n,f), 242mAm(n,f), and 243Am(n,f) at Energies up to 100 keV","authors":"E. A. Koptelov","doi":"10.1134/s1027451024020320","DOIUrl":"https://doi.org/10.1134/s1027451024020320","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>This paper is an overview of the results obtained by a collaborative team of researchers from the Institute for Nuclear Research, Russian Academy of Sciences (INR RAS), and State Scientific Center of the Russian Federation—Institute of Physics and Power Engineering (SSC RF—IPPE) using the SVZ-100 lead slowing-down neutron spectrometer. The study focuses on measuring the fission cross sections of americium isotopes <sup>241</sup>Am, <sup>242m</sup>Am, and <sup>243</sup>Am when bombarded by neutrons with energies below 100 keV. The high efficiency of the SVZ-100, facilitated by its substantial working-substance mass (100 t of high-purity lead) and neutron generation through proton irradiation with a 209-MeV accelerator at the INR RAS, enables the investigation of neutron-nuclear processes in microgram samples of radioactive nuclides, which is unattainable in experiments using time-of-flight spectrometry. Unique scientific information is acquired through lead slowing-down neutron spectrometry by collaborative research efforts at the INR RAS and SSC RF—IPPE. This information partially fills gaps or complements existing but often contradictory or insufficient data from experiments conducted on both time-of-flight installations and lead slowing-down neutron spectrometers at other research centers. The results of collaboration of the INR RAS and SSC RF—IPPE are documented in international nuclear data repositories, indicating, in several instances, the need for adjustments to recommended approximating and calculated values. Information is given on some implemented and planned studies on neutron fission cross sections of americium isotopes at other centers following completion of the collaboration of the INR RAS and SSC RF—IPPE.</p>","PeriodicalId":671,"journal":{"name":"Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140883929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-07DOI: 10.1134/s1027451024020241
E. A. Batalova, L. V. Kamaeva, I. V. Shutov, M. N. Korolev, M. D. Krivilev
Abstract
We study the processes of the contact melting of AMg6 alloy with a solid Zn–Cu–Al solder and a model Zn–Al alloy, as well as the structure of the contact-melting zone. Sample preparation is carried out in two stages. In the first stage, the solder is mechanically applied (tinned) to the surface of AMg6 plates, and in the second stage, the obtained composite samples are subjected to heat treatment, varying the holding time in the liquid state. According to metallographic analysis, X-ray structural analysis, and differential scanning calorimetry, active interaction between Zn and Al occurs already at the tinning stage, leading to the formation of a developed morphology in the joint area. The presence of copper in the HTS-2000 solder decreases the melting temperature of the Zn–Al alloy by 30–40°C and improves the conditions of contact interaction with the AMg6 matrix. Active zinc diffusion ensures the formation of an extensive melting zone during heat treatment. Regions rich in zinc, upon crystallization, contain the intermetallic phase Zn5Cu, which hinders the formation of intermetallics based on the ZnMg system, preventing embrittlement of the contact zone.
{"title":"Structural Analysis of the Interface of Contact Melting between AMg6 and Zn-Based Alloys","authors":"E. A. Batalova, L. V. Kamaeva, I. V. Shutov, M. N. Korolev, M. D. Krivilev","doi":"10.1134/s1027451024020241","DOIUrl":"https://doi.org/10.1134/s1027451024020241","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>We study the processes of the contact melting of AMg6 alloy with a solid Zn–Cu–Al solder and a model Zn–Al alloy, as well as the structure of the contact-melting zone. Sample preparation is carried out in two stages. In the first stage, the solder is mechanically applied (tinned) to the surface of AMg6 plates, and in the second stage, the obtained composite samples are subjected to heat treatment, varying the holding time in the liquid state. According to metallographic analysis, X-ray structural analysis, and differential scanning calorimetry, active interaction between Zn and Al occurs already at the tinning stage, leading to the formation of a developed morphology in the joint area. The presence of copper in the HTS-2000 solder decreases the melting temperature of the Zn–Al alloy by 30–40°C and improves the conditions of contact interaction with the AMg6 matrix. Active zinc diffusion ensures the formation of an extensive melting zone during heat treatment. Regions rich in zinc, upon crystallization, contain the intermetallic phase Zn<sub>5</sub>Cu, which hinders the formation of intermetallics based on the ZnMg system, preventing embrittlement of the contact zone.</p>","PeriodicalId":671,"journal":{"name":"Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140883476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-07DOI: 10.1134/s1027451024020174
S. I. Supelnyak, V. V. Artemov
Abstract—
Substrates with a layer of anodized aluminum oxide are obtained by one-stage and two-stage anodization. The samples have different porosity in volume and on the surface. Bismuth nanoparticles are obtained by thermal evaporation in an argon medium by condensation onto substrates with a layer of anodized aluminum oxide. The distribution of sizes, shapes, and the quantity of nanoparticles and microparticles is studied from images obtained using a scanning electron microscope. The largest number of nanoparticles (21%) on the sample with a surface layer of aluminum oxide without pores is characterized by a diameter of 70 nm. It is assumed that the presence of pores on the surface affects the migration of deposited atoms and particles of bismuth melt until stable condensation centers are formed. The presence of pores with a diameter from 20 to 100 nm leads to a decrease in the diameter of the most common bismuth nanoparticles from 80 to 40 nm. Nanoparticles with a diameter of 90 nm predominate (25%) in the sample with pores with a diameter from 60 to 220 nm. The largest number of spherical crystallites on all substrates has a diameter of 110 nm. It is found that a uniform distribution of particles is obtained for the sample, whose surface was not subjected to chemical polishing.
{"title":"Formation of Bismuth Nanoparticles on Nanoporous Substrates","authors":"S. I. Supelnyak, V. V. Artemov","doi":"10.1134/s1027451024020174","DOIUrl":"https://doi.org/10.1134/s1027451024020174","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">\u0000<b>Abstract</b>—</h3><p>Substrates with a layer of anodized aluminum oxide are obtained by one-stage and two-stage anodization. The samples have different porosity in volume and on the surface. Bismuth nanoparticles are obtained by thermal evaporation in an argon medium by condensation onto substrates with a layer of anodized aluminum oxide. The distribution of sizes, shapes, and the quantity of nanoparticles and microparticles is studied from images obtained using a scanning electron microscope. The largest number of nanoparticles (21%) on the sample with a surface layer of aluminum oxide without pores is characterized by a diameter of 70 nm. It is assumed that the presence of pores on the surface affects the migration of deposited atoms and particles of bismuth melt until stable condensation centers are formed. The presence of pores with a diameter from 20 to 100 nm leads to a decrease in the diameter of the most common bismuth nanoparticles from 80 to 40 nm. Nanoparticles with a diameter of 90 nm predominate (25%) in the sample with pores with a diameter from 60 to 220 nm. The largest number of spherical crystallites on all substrates has a diameter of 110 nm. It is found that a uniform distribution of particles is obtained for the sample, whose surface was not subjected to chemical polishing.</p>","PeriodicalId":671,"journal":{"name":"Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140883482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-07DOI: 10.1134/s1027451024020265
N. G. Galkin, I. M. Chernev, E. Yu. Subbotin, O. A. Goroshko, S. A. Dotsenko, A. M. Maslov, K. N. Galkin, O. V. Kropachev, D. L. Goroshko, A. Yu. Samardak, A. V. Gerasimenko, E. V. Argunov
Abstract
Polycrystalline and epitaxial iron silicide (FeSi) films with thicknesses of 3.2–20.35 nm are grown on a Si(111) substrate using solid-phase and molecular-beam epitaxy at 350°C, as confirmed by X-ray diffraction data. Morphological studies reveal that the films grown by solid-phase epitaxy are continuous and smooth with a root-mean-square roughness ranging from 0.4 to 1.1 nm, while those grown by molecular-beam epitaxy exhibit increased roughness and consist of coalesced grains with sizes up to 1 μm and a pit density of up to 1 × 107 cm–2. In the case of solid-phase epitaxy, an increase in the thickness leads to incomplete silicide formation and the emergence of a layer of disordered iron silicide with a thickness ranging from 10 to 20 nm, possibly with an excess of iron. This is confirmed by a change in the nature of the temperature dependence of the resistivity ρ from semiconductor to semimetallic, which leads to a decrease in the resistivity by 1.5–2 times. The nonmonotonic character of the temperature dependence of the resistivity ρ(T) for an ultrathin FeSi film with a thickness of 3.2 nm is identified, exhibiting a maximum around 230–240 K, a rising segment from 160 to 65 K with Eg = 14.8 meV, and further unsaturated growth down to 1.5 K. As the thickness of the FeSi films grown by molecular-beam epitaxy increases, the minimum and maximum are not observed, but the nonmonotonic trend of ρ(T) with decreasing temperature and the opening of the band gap Eg = 23 meV are preserved. The possible reasons for the observed effects in the ρ(T) dependences are considered. An anomalous Hall effect is detected in ultrathin and thin FeSi films grown by solid-phase and molecular-beam epitaxy, respectively, which confirms the weak ferromagnetic properties of the films. The results demonstrate the feasibility of growing and controlling the properties of ultrathin and thin FeSi films on silicon using methods of solid-phase and molecular-beam epitaxy, providing them with unique transport and magnetic properties not present in single crystals.
{"title":"Structural, Transport, and Magnetic Properties of Ultrathin and Thin FeSi Films on Si(111)","authors":"N. G. Galkin, I. M. Chernev, E. Yu. Subbotin, O. A. Goroshko, S. A. Dotsenko, A. M. Maslov, K. N. Galkin, O. V. Kropachev, D. L. Goroshko, A. Yu. Samardak, A. V. Gerasimenko, E. V. Argunov","doi":"10.1134/s1027451024020265","DOIUrl":"https://doi.org/10.1134/s1027451024020265","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Polycrystalline and epitaxial iron silicide (FeSi) films with thicknesses of 3.2–20.35 nm are grown on a Si(111) substrate using solid-phase and molecular-beam epitaxy at 350°C, as confirmed by X-ray diffraction data. Morphological studies reveal that the films grown by solid-phase epitaxy are continuous and smooth with a root-mean-square roughness ranging from 0.4 to 1.1 nm, while those grown by molecular-beam epitaxy exhibit increased roughness and consist of coalesced grains with sizes up to 1 μm and a pit density of up to 1 × 10<sup>7</sup> cm<sup>–2</sup>. In the case of solid-phase epitaxy, an increase in the thickness leads to incomplete silicide formation and the emergence of a layer of disordered iron silicide with a thickness ranging from 10 to 20 nm, possibly with an excess of iron. This is confirmed by a change in the nature of the temperature dependence of the resistivity ρ from semiconductor to semimetallic, which leads to a decrease in the resistivity by 1.5–2 times. The nonmonotonic character of the temperature dependence of the resistivity ρ(<i>T</i>) for an ultrathin FeSi film with a thickness of 3.2 nm is identified, exhibiting a maximum around 230–240 K, a rising segment from 160 to 65 K with <i>E</i><sub>g</sub> = 14.8 meV, and further unsaturated growth down to 1.5 K. As the thickness of the FeSi films grown by molecular-beam epitaxy increases, the minimum and maximum are not observed, but the nonmonotonic trend of ρ(<i>T</i>) with decreasing temperature and the opening of the band gap <i>E</i><sub>g</sub> = 23 meV are preserved. The possible reasons for the observed effects in the ρ(<i>T</i>) dependences are considered. An anomalous Hall effect is detected in ultrathin and thin FeSi films grown by solid-phase and molecular-beam epitaxy, respectively, which confirms the weak ferromagnetic properties of the films. The results demonstrate the feasibility of growing and controlling the properties of ultrathin and thin FeSi films on silicon using methods of solid-phase and molecular-beam epitaxy, providing them with unique transport and magnetic properties not present in single crystals.</p>","PeriodicalId":671,"journal":{"name":"Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140883830","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-07DOI: 10.1134/s1027451024020381
N. P. Stepanov
Abstract
Upon studying the optical properties of solid solutions of p-type Bi2Te3–Sb2Te3 in the infrared range, it is found that in the single crystal Bi0.6Sb1.4Te3, deformation of the reflection-coefficient spectra is observed in the frequency range of observation of the plasma resonance of free charge carriers. Deformation of the plasma edge increases with a decrease in temperature. Using the Kramers–Kronig dispersion relations from experimental reflection spectra, the spectral dependences of the real ε1 and imaginary parts ε2 of the permittivity function, as well as the energy-loss function characterizing the rate of energy dissipation, are calculated. Splitting of the peak of the energy loss function is found, which indicates the effect on the plasma resonance from another process occurring in the electronic system. It is established that such a process is the transition of electrons between nonequivalent extrema of the valence band. Convergence of the collective and single-particle energies of the electronic system leads to amplification of the electron—plasmon interaction, which is the most probable cause of the observed deformation of the plasma edge.
{"title":"Electron–Plasmon Interaction in Bi2Te3–Sb2Te3 Crystals","authors":"N. P. Stepanov","doi":"10.1134/s1027451024020381","DOIUrl":"https://doi.org/10.1134/s1027451024020381","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Upon studying the optical properties of solid solutions of <i>p</i>-type Bi<sub>2</sub>Te<sub>3</sub>–Sb<sub>2</sub>Te<sub>3</sub> in the infrared range, it is found that in the single crystal Bi<sub>0.6</sub>Sb<sub>1.4</sub>Te<sub>3</sub>, deformation of the reflection-coefficient spectra is observed in the frequency range of observation of the plasma resonance of free charge carriers. Deformation of the plasma edge increases with a decrease in temperature. Using the Kramers–Kronig dispersion relations from experimental reflection spectra, the spectral dependences of the real ε<sub>1</sub> and imaginary parts ε<sub>2</sub> of the permittivity function, as well as the energy-loss function characterizing the rate of energy dissipation, are calculated. Splitting of the peak of the energy loss function is found, which indicates the effect on the plasma resonance from another process occurring in the electronic system. It is established that such a process is the transition of electrons between nonequivalent extrema of the valence band. Convergence of the collective and single-particle energies of the electronic system leads to amplification of the electron—plasmon interaction, which is the most probable cause of the observed deformation of the plasma edge.</p>","PeriodicalId":671,"journal":{"name":"Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2024-05-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140883832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-02DOI: 10.1134/s102745102401004x
E. V. Anikina, D. V. Babailova, M. S. Zhilin, V. P. Beskachko
Abstract
The parameters of molecular hydrogen adsorption on a tetraoxa[8]circulene monolayer were studied using the density functional theory with dispersion interaction corrections (semi-empirical and analytical). The calculations were carried out using two different approaches to the system wave function representation: atomic-like orbital basis set and plane wave basis. Utilizing a less computationally expensive pseudo-atomic basis, it is possible to obtain results for molecular hydrogen adsorption consistent with values calculated with plane waves if the atomic-like basis is optimized and basis set superposition error is corrected for both hydrogen binding energy and geometrical characteristics. Otherwise, the H2 binding energy will be overestimated by 4–6 times (sometimes even more, by 20); and the hydrogen–monolayer distance will be underestimated by 10–20%. The obtained optimized parameters of the pseudo-atomic basis set can be used for further study of the modified forms of the tetraoxa[8]circulene monolayer. Moreover, our calculations showed that the hydrogen binding to a pristine tetraoxa[8]circulene monolayer is predominantly van der Waals with an energy of 60–90 meV, which is several times less than the desired range of 200–600 meV. To achieve such values, it will be necessary to modify the surface of the monolayer, creating more active sorption cites, for example, by decorating it with metals or applying structural defects.
{"title":"Tetraoxa[8]circulene Monolayer as Hydrogen Storage Material: Model with Boys–Bernardi Corrections Within Density Functional Theory","authors":"E. V. Anikina, D. V. Babailova, M. S. Zhilin, V. P. Beskachko","doi":"10.1134/s102745102401004x","DOIUrl":"https://doi.org/10.1134/s102745102401004x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The parameters of molecular hydrogen adsorption on a tetraoxa[8]circulene monolayer were studied using the density functional theory with dispersion interaction corrections (semi-empirical and analytical). The calculations were carried out using two different approaches to the system wave function representation: atomic-like orbital basis set and plane wave basis. Utilizing a less computationally expensive pseudo-atomic basis, it is possible to obtain results for molecular hydrogen adsorption consistent with values calculated with plane waves if the atomic-like basis is optimized and basis set superposition error is corrected for both hydrogen binding energy and geometrical characteristics. Otherwise, the H<sub>2</sub> binding energy will be overestimated by 4–6 times (sometimes even more, by 20); and the hydrogen–monolayer distance will be underestimated by 10–20%. The obtained optimized parameters of the pseudo-atomic basis set can be used for further study of the modified forms of the tetraoxa[8]circulene monolayer. Moreover, our calculations showed that the hydrogen binding to a pristine tetraoxa[8]circulene monolayer is predominantly van der Waals with an energy of 60–90 meV, which is several times less than the desired range of 200–600 meV. To achieve such values, it will be necessary to modify the surface of the monolayer, creating more active sorption cites, for example, by decorating it with metals or applying structural defects.</p>","PeriodicalId":671,"journal":{"name":"Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140883560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-05-02DOI: 10.1134/s1027451024010154
J. V. Osinskaya, S. G. Magamedova, A. V. Pokoev
Abstract
The results of a comprehensive experimental study of the influence of amplitude of the pulsed-magnetic-field intensity on the properties and characteristics of an Al–Si–Cu–Fe aluminum alloy during aging are presented. Data are presented on the modes of thermomagnetic treatment and the results of measurements of the microhardness, lattice parameter, and fine-structure parameters of the alloy aged at a temperature of 175°С for 4 h in a pulsed magnetic field with an intensity amplitude of 79.6–557.2 kA/m and in its absence. The main regularities of changes in the structure and properties of the metal alloy during annealing are formulated.
{"title":"Influence of the Amplitude of the Pulsed-Magnetic-Field Intensity on the Parameters of the Magnetoplastic Effect in Aged Al–Si–Cu–Fe Aluminum Alloy","authors":"J. V. Osinskaya, S. G. Magamedova, A. V. Pokoev","doi":"10.1134/s1027451024010154","DOIUrl":"https://doi.org/10.1134/s1027451024010154","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of a comprehensive experimental study of the influence of amplitude of the pulsed-magnetic-field intensity on the properties and characteristics of an Al–Si–Cu–Fe aluminum alloy during aging are presented. Data are presented on the modes of thermomagnetic treatment and the results of measurements of the microhardness, lattice parameter, and fine-structure parameters of the alloy aged at a temperature of 175°С for 4 h in a pulsed magnetic field with an intensity amplitude of 79.6–557.2 kA/m and in its absence. The main regularities of changes in the structure and properties of the metal alloy during annealing are formulated.</p>","PeriodicalId":671,"journal":{"name":"Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques","volume":null,"pages":null},"PeriodicalIF":0.4,"publicationDate":"2024-05-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140883567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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