


Volume 70, Nº 5 (2025)
- Ano: 2025
- Artigos: 21
- URL: https://modernonco.orscience.ru/0023-4761/issue/view/14164
Edição completa



ДИФРАКЦИЯ И РАССЕЯНИЕ ИОНИЗИРУЮЩИХ ИЗЛУЧЕНИЙ
A new method of phase-contrast microscopy of microobjects using a nanofocusing lens in synchrotron radiation
Resumo
We present the first results of a new experimental method for phase-contrast microscopy of microobjects based on synchrotron radiation and a nanofocusing lens in a conical geometry. In the experiment, a secondary radiation source is formed at the lens focus, located at a short distance from the microobject, enabling the acquisition of its magnified image. Under near-field conditions, the structure of the microobject can be relatively easily retrieved from the experimental image using the transport-of-intensity equation. The experiment was conducted at the KISI-Kurchatov synchrotron radiation source. A model weakly absorbing microobject, namely a commercially available carbon fiber of grade VMN-4, was used. The fiber dimensions and structural features were obtained with submicron spatial resolution, in agreement with the electron microscopy results.
Kristallografiâ. 2025;70(5):715-721



REAL STRUCTURE OF CRYSTALS
Defects initiating fatigue faults in granular alloy EP741NP (part II)
Resumo
Serial section focused ion beam tomography was performed for a three-dimensional reconstruction of the microstructure of defects associated with the formation of fatigue cracks in samples destroyed during fatigue tests. The geometric parameters of defects containing Hf, Nb, Ti, Al, and Ni identified during 3D reconstruction were determined. The morphology of individual particles is represented by a set of shapes that form flat (carpet-like) conglomerates up to tens of microns in size, which cannot be detected by non-destructive testing methods. The revealed morphological features make it possible to propose a set of measures to increase the service life of parts made of granulated heat-resistant nickel alloy EP741NP, which is an important practical result of the study.
Kristallografiâ. 2025;70(5):722-731



СТРУКТУРА НЕОРГАНИЧЕСКИХ СОЕДИНЕНИЙ
STRUCTURAL FEATURES OF TRIS(ETHYLENEDIAMINE)NICKEL(II) DICHLOROIDE DIHYDRATE SINGLE CRYSTALS IN THE TEMPERATURE RANGE 85–293 K
Resumo
The effect of temperature on the structure of single crystals of tris(ethylenediamine)nickel(II)dichloride dihydrate [Ni(en)3]Cl2·2H2O, or [Ni(H2NCH2CH2NH2)3]Cl2·2H2O, was investigated. The rearrangement of the structure with a decrease in temperature from 293 to 85 K was studied using X-ray structural analysis. A threefold decrease in the volume of the unit cell of the crystal was found while maintaining the space group C2/c.
Kristallografiâ. 2025;70(5):732-735



DISSYMMETRIZATION IN EUDIALYTE-GROUP MINERALS. V. CRYSTAL STRUCTURE OF POTENTIALLY NEW MINERAL FROM MOROCCAN PEGMATITE – FIRST HIGH CALCIUM MEMBER WITH Р3-SYMMETRY
Resumo
A study of the crystal structure of high-calcium eudialyte from the Tamazert massif (Morocco) revealed features of its structure that reduce the symmetry of the mineral. The parameters of the trigonal cell are: a = 14.1863(1), c = 30.0703(2) Å, V = 5240.95(4) Å3, sp. gr. P3. The structure, the unit cell of which contains 161 independent positions of atoms, is refined to the final divergence factor R = 4.4% in the isotropic approximation of atomic displacements using 8202 reflexes with F > 3σ(F). The ordering of Ca and Mn atoms in the octahedra of the six-membered rings, Fe and Mn in the M2 positions between the translation-bound rings, as well as Na, H3O, La and K in the extra-framework N positions has been established. The studied mineral is chemically similar to golyshevite and feklichevite, from which it differs in a lower calcium content and a higher manganese content. The main features of the mineral are discussed in comparison with the previously studied high-calcium minerals of the eudialyte group within the framework of the R3 sp. gr. It is shown that a decrease in the symmetry of the structural model of high-calcium representatives of the eudialyte group may be due to the ordering of cations inhabiting the N-positions of the extra-framework part of the structure.
Kristallografiâ. 2025;70(5):736-743



STRUCTURE OF MACROMOLECULAR COMPOUNDS
Composite perfluorinated membranes modified by polyvinyl alcohol cross-linked with sulfosuccinic acid
Resumo
The effect of polyvinyl alcohol (PVA) cross-linked with sulfosuccinic acid on the structure, morphology, physical, mechanical and electrochemical properties of composite membranes made of domestic perfluorinated copolymer, an analogue of Nafion, and PVA was studied. An increase in the amount of cross-linked PVA in the membrane leads to an increase in proton conductivity. The crystallinity of the composites depends on the proportion of the cross-linking agent. The morphology of the membrane surfaces varies significantly: the lower surface has a uniform microstructure, and the upper surface forms three-dimensional folded structures during self-organization of polymer chains in the surface layer. According to energy-dispersive analysis, the two layers of the membrane differ significantly in chemical composition, which is illustrated by the distribution profiles of fluorine across the membrane thickness. The observed structural and morphological features of the membranes explain the differences in their proton conductivity.
Kristallografiâ. 2025;70(5):744-758



ДИНАМИКА РЕШЕТКИ И ФАЗОВЫЕ ПЕРЕХОДЫ
Dynamics of metal-semiconductor and reverse semiconductor-metal phase transitions in sms thin films induced by mechanical and thermal influences
Resumo
The article presents the findings of an investigation of SmS thin films phase transition dynamics, focusing on the semiconductor–metal transition induced by mechanical polishing and the reverse thermally induced metal–semiconductor transition. The results demonstrate that the reverse phase transition occurs during the sample cooling within the temperature range of 408–373 K. The change of phase and element composition of thin films is observed during the aforementioned phase transitions within the surface layer. The findings suggest that SmS thin films can be considered as structures with predictable and required phase transition dynamics, making them promising candidates for engineering functional materials and elements of pressure sensors operating over a wide range.
Kristallografiâ. 2025;70(5):759-766



ФИЗИЧЕСКИЕ СВОЙСТВА КРИСТАЛЛОВ
Surface properties and nucleation of linear acene crystals under growth from vapor and solution
Resumo
The paper presents the results of modeling the surface energy of the (100), (010), (001), (110) and (110) faces of linear acene crystals (naphthalene, anthracene, tetracene and pentacene) using the OPLS force field method and the density functional theory of the B3LYP/6-31G(d,p) level. The modeling was performed using the single crystal X-ray diffraction refined crystal structures of linear acenes. For anthracene, tetracene and pentacene crystals, the surface energy of the (001) face was experimentally estimated using the contact angle method. Expressions for the critical sizes of crystal nuclei in homogeneous and heterogeneous processes under conditions of growth from vapor and solution were obtained and analyzed using the classical thermodynamic approach and taking into account the anisotropy of the surface energy.
Kristallografiâ. 2025;70(5):767-782



Electrophysical Properties Anisotropy of La3Ga5SiO14 Langasite Crystals Doped with Cr and Mn Ions
Resumo
The effect of impurity cations on the optical and electrophysical properties of La3Ga5SiO14 crystals (sp. gr. P321), inactive and activated by Cr and Mn ions (1000 ppm), is shown. The optical properties of these crystals indicate different mechanisms of point defect formation, which leads to differences in their electrophysical properties. For the La3Ga5SiO14:Cr crystal, direct-current electrical conductivity was measured using impedance spectroscopy in parallel (σ c) and perpendicular (σ^c) to the optical axis in the temperature range 673-825 K and static permittivity ε c and ε^c at 297 K. A comparison was made with the results of previously published measurements for La3Ga5SiO14:Mn.
Kristallografiâ. 2025;70(5):783-789



Anisotropy and microscopic aspects of ion transport in Li2B4O7 crystals
Resumo
The molecular dynamics method is used to study the features of ion transport in lithium tetraborate Li2B4O7 crystals with vacancy disorder. It is shown that ion transport caused by lithium ions is anisotropic. The highest values of diffusion coefficients are observed along the c-axis and amount to DLi ~ 1×10–6 cm2/s at temperatures close to the melting point. It is shown that lithium ions jump over distances from 1.5 to 3.5 Å via the vacancy mechanism, and the length of correlated jumps can reach 6 Å.
Kristallografiâ. 2025;70(5):790-799



ПОВЕРХНОСТЬ, ТОНКИЕ ПЛЕНКИ
Studying the X-ray absorption fine structure spectra of a protein monolayer on liquids. The possibilities of multi-pass technique.
Resumo
For the first time, the extended fine structure of the absorption spectra for a protein monolayer on a liquid surface has been measured. We used as a test object human serum albumin treated with zinc chloride solution at a critically low concentration (3.6 × 10–7 M), which is comparable to the zinc concentration in blood serum. A multi-pass technique for detecting fluorescence radiation under total external reflection conditions was applied. The temporal stability of the Zn K-edge absorption spectra was examined using weighted regression analysis. It is shown that the error of the oscillating part of the total spectrum did not exceed 1%, which allowed to determine the radius of the first coordination sphere with an accuracy of ±0.01 Å.
Kristallografiâ. 2025;70(5):800-809



Partially Disordered Crystalline State in a Thin Ge2Sb2Te5 Film: Manifestation of Thermally Induced Nanoscale Effect
Resumo
Using a pulsed electron diffraction instrument, a phase transition in a ~10 nm Ge2Sb2Te5 (GST) film was studied upon heating it from room temperature to ~ 400°C. During crystallization of a free-standing amorphous sample, the formation of a hexagonal GST phase was detected, for which mixing Sb and Ge leads to a formal violation of translational symmetry and unit cell symmetry. However, upon heating an identical amorphous GST film on a carbon membrane, the crystalline state turned out to be represented only by a cubic phase. Within the framework of the Phillips theory, a qualitative explanation is proposed for such a nanoscale effect in GST, which opens up new possibilities for controlling structural ordering in phase-change memory materials (PCMM).
Kristallografiâ. 2025;70(5):810-816



НАНОМАТЕРИАЛЫ, КЕРАМИКА
Preparation of entropy-stabilized fluoride phases of fluorite structure by coprecipitation from aqueous
Resumo
Using the method of co-precipitation from aqueous solutions of nitrates, nano-sized polysubstituted solid solutions containing from 3 to 8 di- and trivalent cations in different quantitative ratios, with the general formula Mn1−xRmxF2+x, where M = Ca, Sr, Ba, Pb, R = La, Gd, Dy, Yb, n = 3 and 4, m = 0, 1, 2 and 4 and x varies from ~0.07 to ~0.3 for different cation compositions, were obtained. All of them retain the fluorite structure (structural type CaF2, space group Fm3m). The possibilities of precipitation of mixed solid solutions in different combinations of cations and using different fluorinating agents are considered. It is shown that the obtained solid solutions are medium- and high-entropy phases.
Kristallografiâ. 2025;70(5):817-823



Conduction Band Electronic States of Fluorine-Substituted Furan-Phenylene Co-Oligomer Film on the Surfaces of Silicon and Zinc Oxide
Resumo
The results of the study of low-energy secondary electronic spectra of films of fluoro-substituted furan-phenylene co-oligomer in the energy range from 5 to 20 eV above EF are presented. Thermal vacuum deposition of films with a thickness of 8–10 nm was performed on the surface of (SiO2)n-Si substrates and layer-by-layer deposited ZnO. The collocation of the main maxima of the density of the electronic states in the conduction band of the studied films and the properties of the potential barrier between the films and the substrate surfaces were determined. The surface topography of thin films of fluorine-substituted furan-phenylene co-oligomer was studied by atomic force microscopy. The films on the ZnO surface have a granular structure with a grain diameter in the surface plane of about 100 nm. On the (SiO2)n-Si surface, the grains have an elongated shape, characteristic of microwhiskers.
Kristallografiâ. 2025;70(5):824-829



A New Approach for Synthesizing Ultrathin Hexagonal Boron Nitride Nanoparticles Through Two-Step Thermal Treatment
Resumo
A method for obtaining hexagonal boron nitride (h-BN) nanoparticles 2–10 nm in size with a crystallinity of up to 99% has been developed. The method is based on two-stage heat treatment at temperatures of 600 and 1000°C using boric acid, urea, nitrogen and hydrogen. X-ray phase analysis, high-resolution transmission electron microscopy, electron diffraction in the selected area, and analysis of electron density maps confirmed the hexagonal structure of h-BN with an interplane distance of 3.3 Å, a narrow size distribution, and a uniform distribution of elements in the material. The proposed approach eliminates the use of toxic ammonia, is energy efficient and suitable for industrial scale. The resulting nanoparticles can be used in tribological coatings and lubricants.
Kristallografiâ. 2025;70(5):830-836



CRYSTAL GROWTH
Growth Features of the Guanylurea Hydrogen Phosphite Single Crystal
Resumo
The article presents the results of the study of aqueous solutions of guanylurea hydrophosphite (GUHP), in particular the isothermal cut of the phase diagram in the system of initial reagents for the synthesis of GUHP salt at 25 and 45°C. The solubility of GUHP in water was studied depending on pH. The growth conditions of bulk crystals were determined. The indexing of GUHP crystal faces was carried out. For the first time, the features of the real structure of GUHP single crystals were studied depending on the growth conditions.
Kristallografiâ. 2025;70(5):837-845



Growth and Some Properties of Mixed Crystals of Non-Isostructural Series of Nickel and Cobalt Sulphates Hexahydrates
Resumo
The dependence of the solubility of NixCo1–xSO4·6H2O (x = 0–1) on the composition of the solution at a temperature of 45°C was obtained. It has been established that an increase in temperature leads to a shift in the point of non-invariant equilibrium of the tetragonal and monoclinic phases towards a higher concentration of cobalt in solution. A thermogravimetric study has shown that as the Co content in the crystal increases, its thermal stability decreases. The spectral characteristics of crystals of different compositions have shown that the crystal can be used as a UV filter. The habitus of a NixCo1–xSO4·6H2O monoclinic crystal obtained from a solution of the composition NiSO4 : CoSO4 = 50 : 50 wt. % has been determined.
Kristallografiâ. 2025;70(5):846-855



Thermoluminescence of dense β-Ga2O3 ceramics synthesized by gas-thermal spraying
Resumo
The paper presents the results of studying the structural and phase composition, optical and thermoluminescent properties of β-Ga2O3 ceramic samples obtained by plasma gas-thermal spraying from the perspective of its application as a luminescent material. Both synthesized samples and those that had undergone post-growth high-temperature and plasma treatment were studied. It is shown that synthesized ceramic samples without additional processing do not provide the necessary sensitivity to radiation due to the high concentration of their own F-type defects, and the thermoluminescence peak is located at a temperature of 350°C, which is inconvenient for registration. Samples of β-Ga2O3 ceramics with post-growth high-temperature and plasma treatment, high thermoluminescence yield and thermoluminescence peak located at 120°C are competitive in comparison with thermoluminescent detectors on the market when irradiated with doses in the range of 0.2–2.5 Gy.
Kristallografiâ. 2025;70(5):856-864



ПРИБОРЫ, АППАРАТУРА
COMPLEX STUDY OF THE INTERNAL STRUCTURE OF POLYMERIC SPONGE MATRIXES IN THE PROCESS OF A TISSUE-ENGINEERED ARRAGEMENT
Resumo
The article presents the approaches of a complex study of the 3D structure of a polymeric spongy matrix based on polylactide using X-ray microtomography without staining in combination with a non-invasive method of scanning pulsed acoustic microscopy and energy-dispersive X-ray microanalysis. Comparative studies of pure matrix samples, in vitro samples kept in a culture medium and after their implantation in vivo were conducted. The use of a complex of non-invasive methods revealed changes in the microstructure, including matrix degradation processes in a culture medium, after incubation with cells and implantation in a laboratory animal.
Kristallografiâ. 2025;70(5):865-873



Experimental Setup for Synchrotron Studies of Materials under Influence of External Magnetic Fields
Resumo
A specialized experimental setup has been designed and manufactured for X-ray diffraction studies under the influence of external magnetic fields on the sample. The setup includes a set of precision automated electromechanical drives that enable orientation of the permanent magnet-based magnetic system along various crystallographic directions of the studied sample. The system provides automated variation of the external magnetic field strength and direction during the experiment. The setup is compatible with blow-out type temperature attachments, allowing for research within a wide temperature range. The specified performance characteristics of the setup and its high parameter stability have been validated through a series of experiments with X-ray scattering near absorption edges using iron borate single crystals.
Kristallografiâ. 2025;70(5):874-880



The design of the crystals structure study. I. Optimization of data collection on modern diffractometers
Resumo
The disadvantages of the “strategy” scan-lists for diffraction experiments created by the diffractometer software are shown. The reason for these disadvantages is that the traditionally used target function has a limited, local meaning, for example, to obtain the best coverage of the reciprocal space. An approach is proposed that implements the principle of statistical randomization of the experiment and makes it possible to achieve the strategic goal of structural analysis – obtaining a model capable of reflecting the subtle details of the atomic structure. A scan-list balanced by most factors has been found, which in less time leads to obtaining experimental data of significantly higher quality than traditional lists. The use of a reference crystal, previously measured dozens of times on diffractometers around the world, has shown the advantage of experimental data obtained by a new method. Increasing the balance and accuracy of the data resulted in a maximum improvement in the values of the refinement criteria to R1/wR2 = 0.53/0.59% and Δρ = –0.47/+0.30 e/Å3. The achievement of the strategic goal of the research of the reference crystal (confirmation of the anharmonic model of atomic displacement parameters) could be confirmed not only by the “purification” of difference Fourier syntheses of electron density, which is sometimes visual and subjective, but also by a statistically flawless decrease in the R-factors of refinement by 30–40 relative %. Data of such high quality are needed to study the dynamics of structural models under external conditions, for the detection and modeling of phase transitions, critical points, bio- and chemical activity of compounds, verification of computational methods of structures.
Kristallografiâ. 2025;70(5):881-889



COMBINING THE RESULTS OF NEUTRON AND SYNCHROTRON TOMOGRAPHY
Resumo
When studying the internal structure of objects consisting of several dissimilar parts by computer tomography, the necessity of using different types of radiation, which interact with matter in different ways, may arise. For example, synchrotron radiation and thermal neutrons have such properties. In this case, a method for joint analysis of data obtained under different conditions should be developed. A method for combining three-dimensional arrays based on determining the coordinates of four reference points and an affine transformation of the coordinate system is considered. Examples of combining results of studying cultural heritage objects using neutron and synchrotron tomography are given.
Kristallografiâ. 2025;70(5):890-896


