Implantation of argon and oxygen ions into the surface of iron in a pulse-periodic mode has been carried out. The chemical compound of ion-modified layers of iron has been studied by energy-dispersive X-ray spectroscopy (EDX), the local atomic structure of the surface has been studied by XAFS (X-ray Absorption Fine Structure) and spectroscopy of electron energy loss fine structures (EELFS). It is shown that irradiation by ions in the oxygen-argon sequence leads to more significant changes in both the chemical state of iron and the local atomic structure of a thin surface layer than irradiated by an argon ion alone.

АННОТАЦИЯ.В настоящей работе для исследования локальной атомной структуры металлического титана и карбида титана TiC использовался метод анализа тонкой структуры спектров энергетических потерь электронов, который является XAFS (X-ray Absorption Fine Structure) -подобной методикой.Исследование проведено на лабораторном Оже-микроанализаторе Jamp 10S (Jeol, Япония).Глубина анализируемого слоя составила не более 5 нм.Получены параметры локального окружения относительно атома титана

The results of an investigation of the chemical composition, structure, topography, and mechanical properties of surface layers of armco-iron after implantation of nitrogen ions under various conditions are given. Using X-ray electron spectroscopy, the implanted nitrogen distribution profiles are determined and the formation of nonstoichiometric iron nitrides and oxynitrides is shown. Using X-ray analysis and electron energy-loss spectroscopy of dimensional fine structures, the atomic and local atomic structure of the ion-modified layers is studied.

Методами рентгеновской фотоэлектронной спектроскопии, рентгеноструктурного анализа, спектроскопии протяженных тонких структур энергетических потерь электронов и спектроскопии комбинационного рассеяния света изучены химический состав, межатомная химическая связь и особенности атомной структуры наноразмерных углеродных пленок на поверхности железа, полученных магнетронным напылением, до и после ионно-лучевого перемешивания. В зоне ионно-лучевого перемешивания обнаружены структурные неоднородности и нестехиометрические карбиды железа. Определены параметры локальной атомной структуры сверхтонкого поверхностного слоя и переходной области "углеродная пленка-металл". Работа выполнена при финансовой поддержке РФФИ (проект N 16-43-180765) и проекта УМНИК, дог. N 9302 ГУ2015. DOI: 10.21883/FTT.2017.03.44176.315

The chemical composition, interatomic chemical bonds, and specific features of the atomic structure of nanosized carbon films on the surface of iron, which were prepared by magnetron sputtering before and after ion-beam mixing, have been investigated using X-ray photoelectron spectroscopy, X-ray diffraction analysis, extended electron energy loss fine structure spectroscopy, and Raman spectroscopy. It has been found that, in the ion-beam mixing region, there are structural inhomogeneities and nonstoichiometric iron carbides. The parameters of the local atomic structure of an ultrathin surface layer and the “carbon film–metal” transition region have been determined.

The regularities of the formation of the chemical composition of thin surface layers of Cu–Mn alloy under irradiation with oxygen ions in the pulse-periodic mode with different parameters of exposure are investigated by X-ray photoelectron spectroscopy (XPS). We study the distribution patterns and chemical state of the alloy elements in the ion-implanted layers, depending on the dose and energy of irradiation. It is found that with increasing irradiation dose, the alloy components are redistributed in the surface layers, and increasing ion energy leads to decomposition of the initial solid solution.

В настоящей работе рассматривается возможность исследования локальной атомной структуры поверхности вещества методом анализа протяженных тонких структур спектров энергетических потерь электронов. Показаны преимущества метода, ограничения и рассмотрены перспективы развития.

A technique for determining parameters of the local atomic structure of a manganese-oxygen system by the extended energy loss fine structure method has been proposed. Experimental extended energy loss fine structure spectra of the clean surface of metallic manganese and its stoichiometric oxides have been measured. Normalized oscillating portions have been separated from the experimental spectra and analyzed by solving the inverse problem using the Tikhonov regularization. The parameters of the local atomic structure of the objects under study, i.e., coordination numbers, bond lengths, and their variance parameters, have been determined.

In this paper, the possibility of studying the local atomic structure of a substance surface by means of analysis of extended fine structures of the electron energy-loss spectra (extended energy-loss fine structure (EELFS) spectroscopy) is considered. The possibilities, restrictions, and the prospects for development of this method are considered.

The formalism of collision theory was used to describe the formation of extended electron energy loss fine structures taking into account multipolarity of the electron-impact excitation of internal atomic layers, and the formation of extended secondary electron fine structures taking into account the first and second order nonradiative relaxation of excited state of the electronic subsystem of a sample. The extended electron energy loss fine structures, extended secondary electron fine structures, and corresponding oscillating parts were obtained in the experiments. The experimental and calculated data showed good agreement.

The carbon distribution in the Mg-C composites produced by ball milling of elemental magnesium with amorphous carbon and graphite powder was studied by X-ray diffractometry (XRD), transmission electron microscopy (TEM), Auger electron spectrometry (AES) and X-ray photoelectron spectrometry (XPS). Specific surface area of the composites was characterized by BET-method. It was found that a thin carbon coating layer on the surface of individual particles is formed. This carbon layer prevents particles agglomeration and promotes the magnesium powdering. A possible structure model of the magnesium-carbon composite has been proposed. (C) 2010 Elsevier B.V. All rights reserved.

Results of research into the structure and chemical inhomogeneity of bimetallic compounds obtained by explosion welding and arc centrifugal deposit welding, by the thermal e.m.f. method, are covered.

The local atomic structure and surface morphology of thin semiconductor films of Ge have been studied via extended X-ray absorption fine structure spectroscopy and atomic force microscopy. The films have been obtained by thermal evaporation of a material in an ultrahigh vacuum at different substrate temperatures. The films contain both amorphous and nanocrystalline phases. The percentage of the phases depends on the condensation temperature. The classical linear dependence of grain sizes on condensation temperature T is violated at T=100°C.

A new approach to synthesis of the ordered germanium nanorod arrays using thermal sputtering on the matrices of porous alumina with the ordered channel arrangement is presented. The synthesized filamentary nanostructures were examined by scanning electron microscopy (SEM), EXAFS and XANES spectroscopy. Data on nanorod geometry in arrays, parameters of the local atomic structure such as interatomic distances and coordination numbers for initial samples and those annealed at 450°C in the argon atmosphere, and data on changes in the electronic states near the absorption K -edge were acquired. A comparison was made with the data of EXAFS studies of a continuous Ge film synthesized on a smooth surface of non-porous Al 2 O 3 .