Pub Date : 2024-05-07DOI: 10.1134/s1027451024020289
V. O. Gridchin, S. D. Komarov, I. P. Soshnikov, I. V. Shtrom, R. R. Reznik, N. V. Kryzhanovskaya, G. E. Cirlin
Abstract
In this study, for the first time, the influence of the III/V flux ratio on the structural and optical characteristics of InGaN nanowires grown by plasma-assisted molecular beam epitaxy are investigated. It is found that the formation of InGaN nanowires with a core–shell structure occurs when the III/V flux ratio (taking into account the In-incorporation coefficient) is about 0.9–1.2. At the same time, an increase in the III/V flux ratio from the intermediate growth conditions to metal-rich conditions leads to a decrease in the In content in nanowires from ~45 to ~35%. Samples of this type exhibit photoluminescence at room temperature with a maximum in the range from 600 to 650 nm. A further increase in the III/V flux ratio to ~1.3 or its decrease to ~0.4 lead to the formation of merged nanocolumnar layers with a low In content. The results obtained may be of interest for studying the growth processes of InGaN nanowires and creating RGB light-emitting devices based on them.
{"title":"On the Growth of InGaN Nanowires by Molecular-Beam Epitaxy: Influence of the III/V Flux Ratio on the Structural and Optical Properties","authors":"V. O. Gridchin, S. D. Komarov, I. P. Soshnikov, I. V. Shtrom, R. R. Reznik, N. V. Kryzhanovskaya, G. E. Cirlin","doi":"10.1134/s1027451024020289","DOIUrl":"https://doi.org/10.1134/s1027451024020289","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>In this study, for the first time, the influence of the III/V flux ratio on the structural and optical characteristics of InGaN nanowires grown by plasma-assisted molecular beam epitaxy are investigated. It is found that the formation of InGaN nanowires with a core–shell structure occurs when the III/V flux ratio (taking into account the In-incorporation coefficient) is about 0.9–1.2. At the same time, an increase in the III/V flux ratio from the intermediate growth conditions to metal-rich conditions leads to a decrease in the In content in nanowires from ~45 to ~35%. Samples of this type exhibit photoluminescence at room temperature with a maximum in the range from 600 to 650 nm. A further increase in the III/V flux ratio to ~1.3 or its decrease to ~0.4 lead to the formation of merged nanocolumnar layers with a low In content. The results obtained may be of interest for studying the growth processes of InGaN nanowires and creating RGB light-emitting devices based on them.</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":"140883489","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/s1027451024020290
O. P. Ivanova, A. V. Krivandin, A. A. Piryazev, S. A. Zav’yalov
Abstract
The structure and chemical composition of nanocomposite films based on poly(p-xylylene) with cadmium sulfide (CdS) as a filler were studied by X-ray diffraction and infrared (IR) spectroscopy. The films were synthesized by the codeposition of p-xylylene monomer and CdS vapors on quartz and silicon substrates, had a thickness of ~0.2 and ~1.5 µm and contained 5–90 vol % of CdS. The effect of the filler content and film thickness on polymer matrix and filler structure was demonstrated. The differences in the chemical compositions of the films with thicknesses of ~0.2 and ~1.5 µm were revealed, caused by their partial oxidation upon contact with air after synthesis. The possible influence of hydroxyl groups on the formation of CdS crystalline structures in films was discussed. A correlation was established between the structural transformations upon changes in the CdS content with the previously obtained dependences of the dark conductivity and photoconductivity for films with a thickness of ~0.2 μm.
{"title":"Structural Features of Poly(p-Xylylene)−Cadmium Sulfide Nanocomposite Films","authors":"O. P. Ivanova, A. V. Krivandin, A. A. Piryazev, S. A. Zav’yalov","doi":"10.1134/s1027451024020290","DOIUrl":"https://doi.org/10.1134/s1027451024020290","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The structure and chemical composition of nanocomposite films based on poly(<i>p</i>-xylylene) with cadmium sulfide (CdS) as a filler were studied by X-ray diffraction and infrared (IR) spectroscopy. The films were synthesized by the codeposition of <i>p</i>-xylylene monomer and CdS vapors on quartz and silicon substrates, had a thickness of ~0.2 and ~1.5 µm and contained 5–90 vol % of CdS. The effect of the filler content and film thickness on polymer matrix and filler structure was demonstrated. The differences in the chemical compositions of the films with thicknesses of ~0.2 and ~1.5 µm were revealed, caused by their partial oxidation upon contact with air after synthesis. The possible influence of hydroxyl groups on the formation of CdS crystalline structures in films was discussed. A correlation was established between the structural transformations upon changes in the CdS content with the previously obtained dependences of the dark conductivity and photoconductivity for films with a thickness of ~0.2 μm.</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":"140883829","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/s1027451024020204
Yu. D. Zavorotnev, P. B. Straumal, E. Yu. Tomashevskaya, B. B. Straumal
Abstract
The mutual influence of the primary and secondary order parameters when high pressure torsion is applied is studied. Equilibrium and nonequilibrium cases are considered. The first is realized with a continuous increase in torque, and the second, when studying the transition from one state to another, described by a traveling wave. The consideration is carried out on the basis of Landau’s thermodynamic theory.
{"title":"Possible Behavior of Shear Deformation under High-Pressure Torsion","authors":"Yu. D. Zavorotnev, P. B. Straumal, E. Yu. Tomashevskaya, B. B. Straumal","doi":"10.1134/s1027451024020204","DOIUrl":"https://doi.org/10.1134/s1027451024020204","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The mutual influence of the primary and secondary order parameters when high pressure torsion is applied is studied. Equilibrium and nonequilibrium cases are considered. The first is realized with a continuous increase in torque, and the second, when studying the transition from one state to another, described by a traveling wave. The consideration is carried out on the basis of Landau’s thermodynamic theory.</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":"140883558","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/s1027451024020034
V. A. Andrianov, K. A. Bedelbekova
Abstract
Implantation of heavy ions into metal matrices leads to the creation of a high concentration of radiation defects. X-ray diffraction studies of Mo and Ta foils implanted with 57Fe ions have been carried out. It is shown that the implantation of Fe ions does not significantly affect the lattice parameters. It has been established that irradiation leads to the broadening of diffraction lines and a decrease in the size of crystal grains. The Mo and Ta foils are found to be highly textured, with {100} orientation in the foil plane. Irradiation with Fe ions has no noticeable effect on the texture. However, subsequent annealing at a temperature of 700°С weakens the texture on the irradiated side for Mo and Ta foils without affecting the texture of the nonirradiated side.
摘要在金属基体中植入重离子会产生高浓度的辐射缺陷。对植入 57Fe 离子的 Mo 和 Ta 箔进行了 X 射线衍射研究。研究表明，铁离子的植入不会对晶格参数产生重大影响。辐照会导致衍射线变宽，晶粒尺寸减小。研究发现，Mo 和 Ta 箔具有高度纹理，在箔面具有{100}取向。用铁离子照射对纹理没有明显影响。然而，随后在 700°С 温度下进行退火会削弱钼箔和钽箔辐照面的纹理，但不会影响非辐照面的纹理。
{"title":"Effect of Irradiation on Grain Size and Texture in Mo and Ta Films","authors":"V. A. Andrianov, K. A. Bedelbekova","doi":"10.1134/s1027451024020034","DOIUrl":"https://doi.org/10.1134/s1027451024020034","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>Implantation of heavy ions into metal matrices leads to the creation of a high concentration of radiation defects. X-ray diffraction studies of Mo and Ta foils implanted with <sup>57</sup>Fe ions have been carried out. It is shown that the implantation of Fe ions does not significantly affect the lattice parameters. It has been established that irradiation leads to the broadening of diffraction lines and a decrease in the size of crystal grains. The Mo and Ta foils are found to be highly textured, with {100} orientation in the foil plane. Irradiation with Fe ions has no noticeable effect on the texture. However, subsequent annealing at a temperature of 700°С weakens the texture on the irradiated side for Mo and Ta foils without affecting the texture of the nonirradiated side.</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":"140883699","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}
The preparation of Fe-based wear-resistant coating by high-speed laser cladding method can well solve the problem of poor wear resistance of aluminum alloy surface. However, due to the large expansion coefficient difference of Fe and Al, the Fe-based laser cladding layer on the Al surface often has cracks, poor molding morphology, and poor mechanical properties. In this work, La2O3 is added as an additive in order to improve the morphology and mechanical properties of Fe-based laser cladding layer on the surface of Al alloy. High-speed laser cladding technology was used to prepare the coating of 18Ni300 + XLa2O3(X = 0.5, 1, 1.5, 2 wt %) on ZL205A aluminum alloy. The morphology, microstructure, hardness, wear resistance and heat shock resistance of the cladding layer were studied. The morphology and crack characteristics of the fusion zone were observed by scanning electron microscopy. Under the present test conditions, the addition of La2O3 improved the forming morphology, refined the microstructure of the cladding, and significantly improved the mechanical properties of the cladding. The optimal addition of La2O3 with the best properties was 1.5 wt % which provided: flat cladding surface, absence of internal cracks, refined grain size, improved wear resistance and thermal shock resistance, 47% higher hardness when compared to 18Ni300.
{"title":"Microstructure and Mechanical Properties of Laser Clad18Ni300 Coatings with La2O3 Addition on ZL205A Aluminum Alloy","authors":"Qixiao Xu, Daoyou Zheng, Xiao Chen, Sergey Konovalov, Xizhang Chen","doi":"10.1134/s102745102402037x","DOIUrl":"https://doi.org/10.1134/s102745102402037x","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The preparation of Fe-based wear-resistant coating by high-speed laser cladding method can well solve the problem of poor wear resistance of aluminum alloy surface. However, due to the large expansion coefficient difference of Fe and Al, the Fe-based laser cladding layer on the Al surface often has cracks, poor molding morphology, and poor mechanical properties. In this work, La<sub>2</sub>O<sub>3</sub> is added as an additive in order to improve the morphology and mechanical properties of Fe-based laser cladding layer on the surface of Al alloy. High-speed laser cladding technology was used to prepare the coating of 18Ni300 + XLa<sub>2</sub>O<sub>3</sub>(X = 0.5, 1, 1.5, 2 wt %) on ZL205A aluminum alloy. The morphology, microstructure, hardness, wear resistance and heat shock resistance of the cladding layer were studied. The morphology and crack characteristics of the fusion zone were observed by scanning electron microscopy. Under the present test conditions, the addition of La<sub>2</sub>O<sub>3</sub> improved the forming morphology, refined the microstructure of the cladding, and significantly improved the mechanical properties of the cladding. The optimal addition of La<sub>2</sub>O<sub>3</sub> with the best properties was 1.5 wt % which provided: flat cladding surface, absence of internal cracks, refined grain size, improved wear resistance and thermal shock resistance, 47% higher hardness when compared to 18Ni300.</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":"140883568","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/s1027451024020137
I. V. Nikolaev, N. G. Korobeishchikov
Abstract—
The features of the surface treatment of potassium-gadolinium-tungstate single crystals doped with neodymium ions by low- and high-energy argon cluster ions are considered. Two radically different treatment modes are employed: the low-energy mode for more efficient smoothing of the surface and high-energy for more effective etching of the target. The topography of the target surface is analyzed before and after cluster-ion treatment using atomic force microscopy. It is shown that treatment in the low-energy mode smoothes out irregularities on the target surface formed by chemical and mechanical polishing at an etching depth of less than 100 nm. A comparison is made of the root-mean-square roughness and total roughness of the initial and treated surfaces of potassium-gadolinium tungstate doped with neodymium ions. Survey X-ray photoelectron spectra of the initial surface of a KGd(WO4)2:Nd single crystal and after cluster-ion treatment in various modes are presented. It is demonstrated that the intensities of the potassium and gadolinium peaks decrease after cluster-ion treatment in both modes. A significant decrease in the concentration of potassium atoms in the surface layer of the target is explained by the preferential sputtering of potassium as a lighter chemical element. The mutual decrease in the concentrations of gadolinium and potassium atoms can be explained by the weak bonds of these atoms in the lattice of the KGd(WO4)2:Nd single crystal.
摘要--研究了低能氩簇离子和高能氩簇离子对掺杂钕离子的钆钨酸钾单晶进行表面处理的特点。采用了两种截然不同的处理模式：低能模式更有效地平滑表面，高能模式更有效地蚀刻靶材。使用原子力显微镜分析了集束离子处理前后靶材表面的形貌。结果表明，在蚀刻深度小于 100 nm 的情况下，低能量模式下的处理可抹平靶材表面因化学和机械抛光而形成的不规则面。比较了掺杂钕离子的钆钨酸钾初始表面和处理表面的均方根粗糙度和总粗糙度。展示了 KGd(WO4)2:Nd单晶初始表面和以各种模式进行簇离子处理后的勘测 X 射线光电子能谱。结果表明，钾和钆峰的强度在两种模式下经过团簇离子处理后都有所下降。钾原子作为一种较轻的化学元素被优先溅射，这解释了靶表面层中钾原子浓度的显著下降。钆原子和钾原子浓度的相互降低可以用 KGd(WO4)2:Nd单晶晶格中这些原子的弱键来解释。
{"title":"Features of the Cluster-Ion Treatment of the Surface of a KGd(WO4)2:Nd Single Crystal","authors":"I. V. Nikolaev, N. G. Korobeishchikov","doi":"10.1134/s1027451024020137","DOIUrl":"https://doi.org/10.1134/s1027451024020137","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">\u0000<b>Abstract</b>—</h3><p>The features of the surface treatment of potassium-gadolinium-tungstate single crystals doped with neodymium ions by low- and high-energy argon cluster ions are considered. Two radically different treatment modes are employed: the low-energy mode for more efficient smoothing of the surface and high-energy for more effective etching of the target. The topography of the target surface is analyzed before and after cluster-ion treatment using atomic force microscopy. It is shown that treatment in the low-energy mode smoothes out irregularities on the target surface formed by chemical and mechanical polishing at an etching depth of less than 100 nm. A comparison is made of the root-mean-square roughness and total roughness of the initial and treated surfaces of potassium-gadolinium tungstate doped with neodymium ions. Survey X-ray photoelectron spectra of the initial surface of a KGd(WO<sub>4</sub>)<sub>2</sub>:Nd single crystal and after cluster-ion treatment in various modes are presented. It is demonstrated that the intensities of the potassium and gadolinium peaks decrease after cluster-ion treatment in both modes. A significant decrease in the concentration of potassium atoms in the surface layer of the target is explained by the preferential sputtering of potassium as a lighter chemical element. The mutual decrease in the concentrations of gadolinium and potassium atoms can be explained by the weak bonds of these atoms in the lattice of the KGd(WO<sub>4</sub>)<sub>2</sub>:Nd single crystal.</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":"140883565","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/s1027451024020393
I. A. Viklenko, V. V. Srabionyan, V. A. Durymanov, Ya. N. Gladchenko-Dzhevelekis, V. N. Razdorov, L. A. Avakyan, L. A. Bugaev
Abstract
The paper introduces a method for representing data on the local atomic structure as histograms of pair radial distribution functions categorized by atom types. This method is used to construct a structure descriptor essential for determining the material structure using machine learning and artificial intelligence methods. A distinctive feature of the approach is the simultaneous use of two sets of pair radial distribution functions: for pairs of all atom types and for pairs involving a selected absorbing atom. The developed approach is tested for determining the nearest environment of silver atoms in color centers in sodium-silicate glasses based on the spectra of X-ray absorption near the absorption edge of Ag. The informativeness of the proposed structure descriptor is demonstrated by its ability to recreate a three-dimensional model of the silver color center’s structure from the corresponding pair distance histograms. Using multiple machine-learning methods, we demonstrate that the proposed descriptor enables the high-quality reproduction of X-ray absorption near edge structure (XANES) spectra for color centers in glass within the framework of the finite-difference method, which results in a four-order-of-magnitude cut in the calculation time for the XANES spectra. The constructed machine-learning model establishes a fundamental connection between the atomic structure of color centers in glasses and the silver XANES spectrum, which is essential for determining the structure of glasses.
摘要 本文介绍了一种将局部原子结构数据表示为按原子类型分类的成对径向分布函数直方图的方法。该方法用于构建结构描述符，该描述符对于使用机器学习和人工智能方法确定材料结构至关重要。该方法的一个显著特点是同时使用两组原子对径向分布函数：所有原子类型的原子对和涉及选定吸收原子的原子对。根据银的吸收边缘附近的 X 射线吸收光谱，对所开发的方法进行了测试，以确定钠硅酸盐玻璃中着色中心银原子的最近环境。所提出的结构描述符能够从相应的线对距离直方图中重建银色中心结构的三维模型，从而证明了该描述符的信息量。利用多种机器学习方法，我们证明了所提出的描述符能够在有限差分法框架内高质量地再现玻璃中颜色中心的 X 射线吸收近边缘结构（XANES）光谱，从而将 XANES 光谱的计算时间缩短了四个数量级。所构建的机器学习模型建立了玻璃中颜色中心的原子结构与银XANES光谱之间的基本联系，这对于确定玻璃的结构至关重要。
{"title":"Compact Representation of the Local Atomic Structure of Matter for Machine Learning in XANES-Spectroscopy Data Processing","authors":"I. A. Viklenko, V. V. Srabionyan, V. A. Durymanov, Ya. N. Gladchenko-Dzhevelekis, V. N. Razdorov, L. A. Avakyan, L. A. Bugaev","doi":"10.1134/s1027451024020393","DOIUrl":"https://doi.org/10.1134/s1027451024020393","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The paper introduces a method for representing data on the local atomic structure as histograms of pair radial distribution functions categorized by atom types. This method is used to construct a structure descriptor essential for determining the material structure using machine learning and artificial intelligence methods. A distinctive feature of the approach is the simultaneous use of two sets of pair radial distribution functions: for pairs of all atom types and for pairs involving a selected absorbing atom. The developed approach is tested for determining the nearest environment of silver atoms in color centers in sodium-silicate glasses based on the spectra of X-ray absorption near the absorption edge of Ag. The informativeness of the proposed structure descriptor is demonstrated by its ability to recreate a three-dimensional model of the silver color center’s structure from the corresponding pair distance histograms. Using multiple machine-learning methods, we demonstrate that the proposed descriptor enables the high-quality reproduction of X-ray absorption near edge structure (XANES) spectra for color centers in glass within the framework of the finite-difference method, which results in a four-order-of-magnitude cut in the calculation time for the XANES spectra. The constructed machine-learning model establishes a fundamental connection between the atomic structure of color centers in glasses and the silver XANES spectrum, which is essential for determining the structure of glasses.</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":"140883705","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/s1027451024020368
V. V. Privezentsev, A. P. Sergeev, A. A. Firsov, V. S. Kulikauskas, V. V. Zatekin, E. P. Kirilenko, A. V. Goryachev, V. A. Kovalskiy
Abstract
The results of studying SiO2 films implanted with 64Zn+ ions with a dose of 5 × 1016 cm–2 at energies of 20 and 120 keV and isochronously oxidized for 1 h at temperatures from 400 to 800°C with a step of 100°C are presented. The profiles of Zn and its oxide are studied using Rutherford backscattering and time-of-flight secondary-ion mass spectrometry. The chemical state of zinc and the phase composition of the film are determined by Auger electron spectroscopy and Raman scattering. It is found that after implantation, the zinc distribution has two maxima at depths of 20 and 85 nm, and after annealing at 700°C there is a broadened maximum at a depth of 45 nm. After implantation, a mixture of Zn and ZnO phases is formed in the sample. After annealing at 700°C, only the ZnO phase is formed in the sample, the distribution profile of which has a broadened peak at 45 nm.
{"title":"Study of SiO2 Films Implanted with 64Zn+ Ions and Oxidized at Elevated Temperatures","authors":"V. V. Privezentsev, A. P. Sergeev, A. A. Firsov, V. S. Kulikauskas, V. V. Zatekin, E. P. Kirilenko, A. V. Goryachev, V. A. Kovalskiy","doi":"10.1134/s1027451024020368","DOIUrl":"https://doi.org/10.1134/s1027451024020368","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The results of studying SiO<sub>2</sub> films implanted with <sup>64</sup>Zn<sup>+</sup> ions with a dose of 5 × 10<sup>16</sup> cm<sup>–2</sup> at energies of 20 and 120 keV and isochronously oxidized for 1 h at temperatures from 400 to 800°C with a step of 100°C are presented. The profiles of Zn and its oxide are studied using Rutherford backscattering and time-of-flight secondary-ion mass spectrometry. The chemical state of zinc and the phase composition of the film are determined by Auger electron spectroscopy and Raman scattering. It is found that after implantation, the zinc distribution has two maxima at depths of 20 and 85 nm, and after annealing at 700°C there is a broadened maximum at a depth of 45 nm. After implantation, a mixture of Zn and ZnO phases is formed in the sample. After annealing at 700°C, only the ZnO phase is formed in the sample, the distribution profile of which has a broadened peak at 45 nm.</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":"140883701","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/s1027451024020095
V. S. Mikhailov, P. Yu. Babenko, A. N. Zinoviev
Abstract—
Calculations of the tungsten sputtering yields (the divertor material in the ITER tokamak) by He, Be, N, and O—impurity atoms in the plasma—were carried out at a collision energy of 0.010–100 keV using the Monte Carlo method. To calculate the trajectory of the incident particle, pair potentials obtained within the framework of density functional theory were used. These potentials were corrected for the parameters of the potential well obtained from spectroscopic measurements. The target consisted of tungsten randomly oriented crystals the size of one lattice constant. Next, the trajectories of the recoil particles were calculated using many-particle potentials calculated using density functional theory. Thermal vibrations of target atoms were taken into account. The vibration amplitude was taken to be 0.05 Å, which corresponded to room temperature. The strong dependence of the results on the shape of the surface potential barrier is shown, and the results are presented for two limiting cases of the surface state: a flat surface, when a planar surface potential barrier is realized, and a surface consisting of cones, when a spherical potential barrier occurs. In the experiment, the surface has some roughness, which depends on the experimental conditions. It is shown that the experimental results lie between the limiting cases we considered. Information was obtained on the average energy of sputtered atoms and angular distributions necessary for calculating the entry of impurities into the tokamak plasma.
摘要-采用蒙特卡洛方法计算了等离子体中 He、Be、N 和 O 杂质原子在 0.010-100 千伏碰撞能量下的钨溅射产率（ITER 托卡马克中的分流器材料）。为了计算入射粒子的轨迹，使用了在密度泛函理论框架内获得的对位势。这些电位根据光谱测量获得的电位井参数进行了修正。目标由一个晶格常数大小的钨随机定向晶体组成。接着，使用密度泛函理论计算的多粒子势来计算反冲粒子的轨迹。目标原子的热振动被考虑在内。振动幅度取为 0.05 Å，相当于室温。实验结果表明，表面势垒的形状对实验结果有很强的依赖性，实验结果显示了表面状态的两种极限情况：实现平面势垒时的平面表面和出现球形势垒时由锥形组成的表面。在实验中，表面有一定的粗糙度，这取决于实验条件。实验结果表明，实验结果介于我们考虑的极限情况之间。获得了关于溅射原子平均能量和角度分布的信息，这些信息对于计算杂质进入托卡马克等离子体是必要的。
{"title":"Tungsten Sputtering Yields by Light Impurities of Plasma","authors":"V. S. Mikhailov, P. Yu. Babenko, A. N. Zinoviev","doi":"10.1134/s1027451024020095","DOIUrl":"https://doi.org/10.1134/s1027451024020095","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">\u0000<b>Abstract</b>—</h3><p>Calculations of the tungsten sputtering yields (the divertor material in the ITER tokamak) by He, Be, N, and O—impurity atoms in the plasma—were carried out at a collision energy of 0.010–100 keV using the Monte Carlo method. To calculate the trajectory of the incident particle, pair potentials obtained within the framework of density functional theory were used. These potentials were corrected for the parameters of the potential well obtained from spectroscopic measurements. The target consisted of tungsten randomly oriented crystals the size of one lattice constant. Next, the trajectories of the recoil particles were calculated using many-particle potentials calculated using density functional theory. Thermal vibrations of target atoms were taken into account. The vibration amplitude was taken to be 0.05 Å, which corresponded to room temperature. The strong dependence of the results on the shape of the surface potential barrier is shown, and the results are presented for two limiting cases of the surface state: a flat surface, when a planar surface potential barrier is realized, and a surface consisting of cones, when a spherical potential barrier occurs. In the experiment, the surface has some roughness, which depends on the experimental conditions. It is shown that the experimental results lie between the limiting cases we considered. Information was obtained on the average energy of sputtered atoms and angular distributions necessary for calculating the entry of impurities into the tokamak plasma.</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":"140883557","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/s1027451024020186
V. V. Syshchenko, A. I. Tarnovsky, A. S. Parakhin, A. Yu. Isupov
Abstract
The potential well formed by the repulsive continuous potentials of three neighboring [111] chains in a silicon crystal, for a positively charged particle, exhibits the symmetry of an equilateral triangle, described by the ({{C}_{{3{v}}}}) group. In this case, the previously developed procedure for finding the eigenvalues of the transverse motion energy of channeled positively charged particles (positrons or protons) and the corresponding eigenfunctions of the Hamiltonian, implemented on a square spatial grid, leads to artifacts in numerical modeling. We present a modification of the modeling algorithm based on a hexagonal grid, which takes into account the symmetry of the problem. The results of both approaches are compared, demonstrating the absence of artifacts when using a hexagonal grid. Using numerical methods, all discrete energy levels of the transverse motion of channeled positrons with a longitudinal motion energy of 2, 2.5, 3, 3.5, and 4 GeV in the discussed potential well are found. The developed procedure can be used in studies of manifestations of dynamic tunneling and quantum chaos in channeling.
{"title":"Simulating Quantum States of Positively Charged Particles Channeling along the [111] Direction in a Silicon Crystal","authors":"V. V. Syshchenko, A. I. Tarnovsky, A. S. Parakhin, A. Yu. Isupov","doi":"10.1134/s1027451024020186","DOIUrl":"https://doi.org/10.1134/s1027451024020186","url":null,"abstract":"<h3 data-test=\"abstract-sub-heading\">Abstract</h3><p>The potential well formed by the repulsive continuous potentials of three neighboring [111] chains in a silicon crystal, for a positively charged particle, exhibits the symmetry of an equilateral triangle, described by the <span>({{C}_{{3{v}}}})</span> group. In this case, the previously developed procedure for finding the eigenvalues of the transverse motion energy of channeled positively charged particles (positrons or protons) and the corresponding eigenfunctions of the Hamiltonian, implemented on a square spatial grid, leads to artifacts in numerical modeling. We present a modification of the modeling algorithm based on a hexagonal grid, which takes into account the symmetry of the problem. The results of both approaches are compared, demonstrating the absence of artifacts when using a hexagonal grid. Using numerical methods, all discrete energy levels of the transverse motion of channeled positrons with a longitudinal motion energy of 2, 2.5, 3, 3.5, and 4 GeV in the discussed potential well are found. The developed procedure can be used in studies of manifestations of dynamic tunneling and quantum chaos in channeling.</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":"140883465","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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