An in situ study of the spatial distribution of the piezoelectric properties of an LiNb (1− x ) Ta x O 3 crystal (〈 x 〉 = 0.088) in an external DC electric field was performed by the method of X-ray diffraction of synchrotron radiation at angles close to 180°. The variation of the d 22 piezoelectric coefficient was determined with high accuracy (up to 2%) in local areas by the angular shift of the diffraction maximum under the action of the electric field ( E = 1582 V mm −1 ) applied on the crystal along the Y axis, during scanning along the X and Z directions. A correlation between the piezoelectric strain amplitude and the concentration of tantalum obtained by X-ray fluorescence mapping has been established.

The nonuniform distribution of chemical element ratios in a crystal of nominal composition La 3 (Ga 0.5 Ta 0.5 )Ga 5 O 14 has been determined using X-ray diffraction and X-ray fluorescence mapping on beamline 6.2 of the Kurchatov synchrotron radiation source “KISI-Kurchatov.” The Ga/Ta and La/Ta ratios are shown to increase from the center to the periphery of the crystal growth boule, which is accompanied by an increase in the number of oxygen vacancies leading to a decrease in piezoelectric modulus d 11 . The study is of practical importance for the creation of materials with desired properties.

A spectrometer has been developed at the beamline EXAFS-D station of the Kurchatov synchrotron-radiation source at the Kurchatov Institute National Research Center for the precision determination of relative variations in the lattice parameters of single crystals. The spectrometer allows measurements of small (up to 3 × 10−7) relative variations in the lattice parameter, which may be caused by stoichiometry violation or external actions, e.g., inverse piezoelectric effect. The method of X-ray diffraction in a geometry that is close to backscattering at angles as large as 179.5° is implemented in the spectrometer. Using a synchrotron source, it is possible to select the radiation wavelength for tuning the spectrometer to the near-backscattering diffraction geometry. The equipment of the spectrometer allows simultaneous monitoring of the lattice-parameter variation and mapping of the elemental composition over the crystal surface.

This article presents measurements of the piezoelectric modulus d 11 of a single crystal of lanthanum gallium silicate (LGS, La 3 Ga 5 SiO 14 ). The piezoelectric modulus was measured by X-ray diffraction at angles close to backscattering. Experiments in such schemes are very sensitive to relative changes in the lattice constant in crystals caused by external influences (constant or alternating electric field, mechanical load, temperature change etc .). The development opportunity of the technique is shown, its applicability is evaluated and results of measurement of the LGS single-crystal piezo modulus by the method of diffraction of synchrotron radiation at angles near π are discussed.

В НИЦ Курчатовский институт с использованием комплекса естественнонаучных методов исследован камень с выбитыми изображениями, найденный на р. Пегтымель на Чукотке археологической экспедицией ИА РАН под руководством Е.Г.Дэвлет. Установлены состав и природа минеральных образований на поверхности камня с петроглифами. Выявлен скальный загар , содержащий марганец и потенциально пригодный для датирования. На карте распределения химических элементов в выбивке зафиксированы медь и цинк и предположено их антропогенное происхождение в качестве микрочастиц древнего орудия. Намечена возможная дата создания петроглифов: конец II начало I тыс. до н.э. Подтверждена версия исследователей петроглифов Пегтымеля о том, что рисунки на скалах выбивались металлическими орудиями. Several separated stone blocks with pecked images had been found in the course of the expedition for study the rock art site at the Pegtymel River in the western part of the Chukotka Peninsula. The expedition (2005 2008) was organized by the Institute of Archaeology and lead by Ekaterina Devlet. One of such blocks was taken away from the site to Moscow, which made it possible to carry out recently its study in the Kurchatov Institute with the use of a whole complex of natural-scientific methods. The researchers have identified mineral compounds on the surface of the decorated rock and determined the rock varnish formation on it. Cu Zn particles have been detected in the pecked area. It is possible that the particles were introduced as a result of processing the rock with bronze or brass tool. The date of creation the petroglyphs is proposed as the end of the 2nd beginning of the 1st millennium BC.

The analytical diagnostics of art objects and items of cultural value have become increasingly sought for in modern interdisciplinary studies. Within the natural-science approach, a manuscript is considered as a physical object consisting of materials of two types. The first type comprises various substrates for writing (papyrus, paper, parchment, palm leaves), and the second type includes writing materials (soot ink, iron gall ink, or red lead ink). Textual fragments of ancient parchment manuscripts, including hidden textual fragments, are elementally mapped and digitally imaged with X-ray fluorescence. The collagen structure of the parchment and ink composition are diagnosed.

The performance of a multipurpose synchrotron spectrometer is diversified by installing additional equipment for the studies of diffraction in the Debye–Scherrer geometry. The design of X-ray optics and technical characteristics of the spectrometer are described. Diffraction patterns for polycrystals detected in both the forward and backward hemispheres are illustrated.

The improved X-ray optical scheme, the system of registration, and the measurement procedure of the multifunctional synchrotron radiation spectrometer in the dispersive EXAFS mode are described. The results of the spectrometer energy resolution measurements are given. The advantages and disadvantages of traditional and dispersive EXAFS spectrometers are analyzed. Examples of EXAFS spectra measured in the dispersive mode are given.

The performance of the Kurchatov Institute’s multiporpose synchrotron spectrometer is diversified by adding the equipment for the X-ray fluorescent element analysis. The X-ray optical focusing system of the spectrometer is described. The analysis results for the copper, lead, and gold-nanofilm samples are reported.

A fragment of a text written in red ink is scanned at the X-ray fluorescence analysis station of the Kurchatov synchrotron radiation facility; the element distribution in the scanned region is obtained. The possibility of imaging and reading text fragments using synchrotron radiation is proved.

An X-ray optical system is developed for a station intended for the investigation samples with high locality under extreme conditions, i.e., high pressures and high or low temperatures Various mirrors of total external reflection are considered as options for focusing elements in the system.

Создана аппаратура, развита методика и получены экспериментальные результаты по дифракции Дебая–Шеррера в геометрии обратного рассеяния. Разработан вариант программы обработки дифракционных колец. Обсуждаются перспективы использования методики для целей материаловедения.

Equipment is constructed, a technique is developed, and experimental results on Debye-Scherrer diffraction in the backscattering geometry are obtained. A special program for diffraction ring processing is developed. The prospects for use of this technique for materials science purposes are discussed.

A technique for Debye-Scherrer diffraction in the backscattering geometry is developed at the Kurchatov Synchrotron Radiation source. It is shown that the sensitivity of the method to a relative change in the lattice constant is higher by two orders of magnitude than that in the forward-scattering geometry. The requirements for experimental apparatus are discussed.

На Курчатовском источнике СИ разработана методика Дебая–Шеррера в геометрии обратного рассеяния. Показано, что чувствительность метода к относительному изменению межплоскостного расстояния более чем на два порядка превышает соответствующую чувствительность при прямом рассеянии. Обсуждаются требования к экспериментальной аппаратуре.

A method using intermediate processing of amplitude (energy) spectra is described. The method is an alternative to the known differential discrimination method, which is widely applied in measurements of EXAFS spectra and in Mössbauer and diffraction measurements. The method is efficient in cases in which the radiation spectrum contains lines poorly resolved in the used detector. For example, if weak fluorescence of a low-concentration impurity is detected in a sample against the background of intense fluorescence of the matrix, the described method allows one to noticeably improve the quality of the obtained information.

A method for automatically controlling commercial computer codes is described. The coupling of the automation system of the EXAFS spectrometer controlled by a DOS-operated computer that we developed and the commercial program of a semiconductor-detector control installed on a Windows-operated computer is given as the example. The described complex system is used for the automation of the intermediate processing of amplitude spectra while measuring EXAFS spectra at the Kurchatov Synchrotron Radiation Source.