Search

This work is devoted to the study of the effect of irradiation with Kr15+ and Xe23+ heavy ions with energies of 147 and 220 MeV, respectively, on the change in the optical, structural and strength properties of ceramics ZrO2. Polycrystalline ZrO2 ceramics with a tetragonal type of crystal structure, which are highly resistant to external influences, mechanical strength to cracking, and hardness were chosen as the object of research. The choice of heavy ions Kr15+ and Xe23+ is due to the possibility of simulating the effect of nuclear fission fragments in an atomic reactor, and the choice of irradiation doses of 1 × 1013–1 × 1014 ion/cm2 is due to the possibility of simulating the effects of overlapping defect regions arising along the trajectory of ions in the material. Using the X-ray diffraction method, it was found that in the case of irradiation with heavy ions, an increase in the radiation dose leads to phase transformations of the tetragonal type of the crystal lattice into a cubic one. In this case, for the samples irradiated with Xe23+ ions at an irradiation dose of 1 × 1014 ion/cm2, an almost complete phase transformation is observed. Dependences of changes in strength and optical characteristics on the type of irradiation and dose load have been established.

This article is devoted to the study of the efficiency of thermal annealing of nanostructures for phase transformations of the FeCo – Fe2CoO4/Co3O4-spinel type, as well as the subsequent application of the obtained nanotubes as a basis for anode materials of lithium-ion batteries. The choice of these types of nanotubes for use as a basis for anode materials is due to their structure, as well as the great potential of using spinel structures in this area, interest in which is manifested due to the possibility of accelerating lithiation processes and long-term preservation of the specific capacity of batteries. During the study, it was found that for spinel structures, the formation of oxide growths on the surface of nanotubes, the presence of which is associated with oxidative processes during annealing, is observed. Testing the applicability of these structures as anode materials showed that the formation of oxide spinel structures of type Fe2CoO4/Co3O4 leads to an increase in the number of cycles by 1.5–1.7 times compared to the original nanotubes. The efficiency of increasing the lifetime of anode materials is due to an increase in resistance to degradation of Fe2CoO4/Co3O4 structures, due to the formation of oxide phases, leading to an acceleration of lithation processes.

The aim of this work is to study the radiation damage processes, as well as their subsequent evolution and the effect on the structural, optical and mechanical properties of BeO ceramics. The choice of the type of Kr15+ ions with an energy of 140 meV makes it possible to simulate the kinetics of radiation damage comparable to the effect of uranium fission fragments in a nuclear reaction. Dose loads, which ranged from 1011 to 1015 ion/cm2, make it possible to simulate both single effects of radiation damage in the case of irradiation doses of 1011–1012 ion/cm2, and the effects of overlapping radiation damage and their mutual influence on changes in the properties of ceramics. During the studies carried out, the kinetics of changes in ceramics properties from the radiation dose was established, and the critical doses at which ceramics properties deteriorate sharply were determined. Studies showed that a growth in the radiation dose, leading to an increase in the defective areas overlap probability, leads to grain crushing and an increase in dislocation density, which in turn, leads to a slowdown in degradation processes of the ceramics strength and hardness.

In recent years, ceramic materials based on nitrides are of particular interest, which have great potential to be used as the basis of structural materials. At the same time, great attention is paid to the processes of studying radiation damage and the mechanisms of evolution of radiation defects that cause irreversible structural changes that reduce the operational characteristics of materials. The purpose of this work is to study the mechanisms of radiation damage and helium swelling in ceramics based on aluminum nitride caused by irradiation with low-energy He2+ ions with an energy of 40 keV and radiation doses of 1 × 1016–1 × 1018 ion/cm2. During the research, the dependences of changes in structural, morphological, and strength characteristics on the radiation dose were obtained. The critical values of radiation doses (3–5 × 1017 ion/cm2) for which the degree of radiation damage increases sharply have been established. It was determined that at a dose above 3 × 1017 ion/cm2 there is a sharp increase in structural distortions and deformations, which are due to partial swelling of the crystal lattice, as well as an increase in the concentration of embedded helium. It was found that increasing the irradiation dose to 5–7 × 1017 ion/cm2 leads to a sharp increase in the formation of helium bubbles on the surface, and their rupture with the formation of broken areas in the near-surface layer of ceramics.

This paper presents the results of studying the properties of TeO2-(1-x)ZnO-xSm2O3 glasses synthesized using the method of mechanochemical synthesis and subsequent thermal sintering. The control of the elemental composition was carried out using the method of energy dispersive analysis, the amorphous structure of the glasses was confirmed by the data of the results of measurements of X-ray diffraction. The shielding efficiency was evaluated by such parameters as Radiation protection efficiency, linear and mass attenuation coefficient and gamma radiation absorption, half-value layer and mean free path values. During the research, it was found that TeO2-0.2ZnO-0.8Sm2O3 glasses had the highest shielding efficiency. The results obtained can later be used for the design of protective materials and the development of technological processes for their production.

In this paper, we have reported the vibrational and photoluminescence properties of Ba0.97Bi0.02Ti0.9Zr0.05Nb0.04O3 (BBTZN) polycrystalline perovskite produced via the Molten Salt reaction. The Raman spectrum indicated the chemical disorder in the BBTZN sample, at room temperature. The values optical gap and Urbach energy were evaluated on the basis of the UV–Vis–NIR absorption spectrum. Furthermore, BBTZN compound emitted two peaks at near-infrared light (950 nm and 1040 nm) with 514.5 nm light excitation related to the luminescence of bismuth lower valence states: Bi2+ (2P1/2–X2) and Bi+ (3P0–3P1). The measured activation energy from PL spectra proved that our compound possesses a good thermostability in the temperature range from 10 to 300 K. All the analytical results prove that BBTZN polycrystalline could have some significant potential applications in white luminescent devices.

The paper presents the results of the study of structural, morphological, optical, and mechanical properties of lithium-containing ceramics obtained using the method of mechanochemical solid-phase synthesis. The purpose of this work is to assess the possibility of obtaining lithium-containing ceramics of the two-phase type, as well as the formation effect of the cubic phase of LiTiO2 on changes in the properties of ceramics. The relevance of this study is to obtain new data on the properties of lithium-containing ceramics, which have great prospects in their use as blanket materials for tritium reproduction. During the study, it was found that the formation of the LiTiO2 cubic phase leads to a change in the morphological features of ceramics, with the formation of sphere-like agglomerates of a nanoscale scale. An increase in the contribution of the LiTiO2 phase leads to a shift of the fundamental absorption edge, as well as the appearance of additional absorption bands. During mechanical tests for the determination of resistance to destruction by single compression, it was found that an increase in ceramic density, which is due to an increase in the contribution of the cubic phase, leads to an increase in resistance by 70–85%.

The work is devoted to the study of the possibility of using low-energy irradiation with helium ions to increase the photocatalytic activity of tungsten oxide (WO3) microparticles, if used as catalysts for the decomposition of Rhodamine B. The prospect of this study is to find new ways to solve the problem of increasing the catalytic activity of micro- and nano-particles. During the study, the dependences of changes in the structural and morphological properties of the studied microparticles exposed to irradiation were established, and the effect of irradiation on the increase in the efficiency of decomposition of the organic dye Rhodamine B in aqueous media under UV irradiation was studied. It was found that the use of irradiation with helium ions leads to an increase not only in the rate of photocatalytic reactions, but also in the degree of mineralization, as well as in the efficiency of removing COD from aqueous solutions. Cyclic tests have shown the resistance of the modified microparticles to degradation, as well as the retention of the decomposition efficiency, with a decrease in the degree of mineralization after ten test cycles by 30%. At the same time, unlike the initial microparticles, ionic modification leads to an increase in the resistance of the structure to temporary degradation during cyclic tests.

The densely packed arrays of Ni nanowires of 70 nm diameter and 6-12 μm length were obtained via electrodeposition into porous alumina membranes (PAAMs) of 55-75 μm thickness. The morphology, microstructure and magnetic properties between the room and liquid-helium temperature of Ni nanowires in PAAMs have been investigated using scanning electron microscopy, X-ray diffraction and vibrating sample magnetometry. The crystal structure of the Ni nanowires is fcc with (220) preferred orientation. The magnetic characteristics of the Ni nanowires in PAAMs were compared with the same characteristics of bulk Ni and with other researchers' data. The effect of the porous alumina membrane and the Ni nanowires synthesis conditions on the magnetic characteristics of Ni nanowire arrays has been studied. The coercivity reached more than 750 kOe and the squareness ratio up to 0.65 under the proposed optimal synthesis conditions for Ni nanowires. Magnetic parameters of the densely packed arrays of Ni nanowires allow using them in magnetic recording media, hard disk drives, storage systems and sensors. In addition, such structures are of considerable interest for basic research on nanomagnetism which is significantly different from the magnetic properties of bulk and thin films materials. © The Royal Society of Chemistry. The work was performed with support of State Scientic and Technical Program “Nanotech” (task GBx no 20163522 and no. 2.34), Branch Scientic and Technical Program “Nanotechnology and Nanomaterials” (task no. 1), Act 211 of Government of Russian Federation (contract No. 02.A03.21.0011). Dmitry Lyakhov and Dominik Michels are partially supported by KAUST (baseline funding).

Two technological schemes are considered, as well as the possibilities of their implementation for the manufacture of sealed accelerator tubes based on diodes with magnetic isolation Schematic designs of tubes under development with a laser source of deuterons and an electronic conductivity suppression system are presented. To do this, a sufficiently heat-resistant permanent magnet is included in the vacuum volume of the first tube. Another design of the tube contains a pulsed system for suppressing electronic conductivity using a pulsed magnetic field created by a conical spiral placed inside the tube.

The aim of this research work is to evaluate the efficiency and prospects of using low-energy O2+ ion beams with an energy of 40 keV and irradiation fluences of 1014–5 × 1015 ion/cm2 to increase the photocatalytic activity of thin films based on TiO2. As research methods, methods of atomic force microscopy, energy-dispersive analysis, X-ray diffraction and UV–Vis spectroscopy were applied. According to the obtained data on changes in surface morphology as a result of irradiation, the main changes are associated with the formation of chillocks on the surface at doses of 1014–1015 ion/cm2, followed by an increase in the size and density of chillocks, and for samples irradiated with a dose of 5 × 1015 ions/cm2, the emergence of wavy formations on the surface associated with reorientation of grains and structural disordering is observed. As shown by the results of X-ray data, the main structural changes in the irradiated films are associated with partial fragmentation of grains and their subsequent reorientation at high radiation doses. In the case of irradiated samples, a decrease in the band gap is observed, which is caused by a change in the electron density as a result of irradiation. The results of the photochemical decomposition of water and the production of hydrogen showed that the use of modified thin films led to an increase in the rate of hydrogen production by 5.4–8 times, depending on the irradiation dose of the samples.

The work is devoted to the study of the effect of lithium doping on the structural and electrical properties of ferroelectric ceramics LixSr1-xTiO3. The concentration of lithium dopant varied from x = 0.01 to 0.15. It was found that an increase in lithium during the synthesis leads to phase transformations of the type SrTiO3/TiO2 → SrTiO3/TiO2/Li2Ti3O7 → SrTiO3/Li2Ti3O7. According to the data obtained, the capacitance value for samples with a lithium content in the structure x = 0–0.01 is 0.05–0.07*10-9 F*cm-1, an increase in lithium concentration to x = 0.05–0.1 in the structure leads to an increase in the capacity value of 0.6*10-9 F*cm-1 with a further drop in the frequency range 103–105 Hz to 0.05–0.07*10-9 F*cm-1, and at a lithium concentration of x = 0.15, the capacitance increases sharply and retains its value throughout frequency range within the range of 0.9–1.2 0.05–0.07*10-9 F*cm-1. According to the data obtained, the deviation ΔT from the Curie-Weiss law for the studied ceramics is no more than 4, while the value of the Curie-Weiss constant is characteristic of ferroelectrics. The small value of ΔT indicates that for the initiation of phase transitions from tetragonal/orthorhombic to cubic at temperatures not exceeding 100–110 °C.

The paper presents the results of a study of changes in the phase composition and dielectric properties of perovskite-like composites of the LiBaZrOx type depending on the temperature of the heat treatment. According to the data obtained, the initial samples obtained by the solid-state synthesis method are a three-phase system with the dominance of the orthorhombic phase ZrO2, the average nanoparticle size of which consists of composites, does not exceed 90–110 nm. As a result of thermal annealing, the dependences of phase transformations, as well as the dynamics of structural ordering with the formation of core-shell structures at an annealing temperature of 1000 °C, were established. The reduction of distortions and deformations of the crystal structure as a result of thermal annealing leads to an improvement in ferroelectric properties, as well as a decrease in the Curie temperature characteristic of the maximum dielectric constant. The weak dependence of the change in the dielectric constant with increasing frequency in the temperature range exceeding the Curie temperature indicates the relaxor nature of the properties of composites.

In this article, NiFe2O4 nanoparticles (NPs) were prepared by co-precipitation method with subsequent thermal annealing leading to obtainment NPs with average sizes of 78 nm. Structure and magnetic analysis were performed by X-ray diffraction, transmission electron microscopy, Mossbauer spectroscopy and vibrating sample magnetometry techniques. Stability of NiFe2O4 NPs was evaluated in PBS solution during 20 days. The toxicity of prepared NPs was evaluated in vitro using different cancer cell lines: HeLa (cervical cancer cell), PC-3 (prostate cancer cell). Fibroblasts like cells of L929 obtained from subcutaneous adipose tissue of mouse were used as normal cells. Results indicate successful synthesis of NiFe2O4 NPs that exhibit low cytotoxicity in concentration range from 1 to 100 μg/ml. Presented physical and biological results indicate the possibility of application investigated magnetic nanoparticles in hyperthermia, targeted drug delivery, magnetic resonance imaging or cell separation.

The interest in thin films based on chalcogenides, among which CdSe structures stand out, is due to the great prospects for their use as various photocatalysts, microelectronic devices, etc. However, despite the large number of scientific works in the field of studying the properties of semiconductor thin films, there are still many unresolved issues. In this regard, the main goal of this work is a systematic study of the influence of electrochemical deposition conditions, in particular, in the applied potential difference, on the change in the structural and optical properties of CdSe-based thin films, as well as assessing the applicability of the obtained thin films in photocatalytic decomposition reactions of tetracycline hydrochloride. Atomic force microscopy, X-ray diffraction, energy-dispersive analysis, and UV spectroscopy were used as research methods. In the course of the study, the dependences of the change in the stoichiometry of thin films on the applied potentials difference were established, in particular, it was found that an increase in the potential difference of more than 1.5 V leads to an increase in cadmium in the structure of the films. By the method of X-ray diffraction it was found that for thin films obtained with an applied potentials difference in of 1.75–2.0 V, in addition to the main hexagonal phase of CdSe, the appearance of weak diffraction reflections characteristic of the hexagonal phase of cadmium is observed. The prospects of using synthesized thin films as photocatalysts, which showed good photocatalytic activity over time, which ranged from 50 to 70%, are shown. In this case, films with a nonstoichiometric ratio of elements have the highest photocatalytic activity.

The aim of this work is to assess the prospects of using CuBi2O4 composite films of various thicknesses as protective coatings against exposure to ionizing radiation of up to 150 MeV and doses of 1 × 1013–1015 ion/cm2, characteristic of the effects of overlapping cascade defects in the target. The relevance and novelty of the study lies in the search for alternative sources of screening for the effects of radiation damage to microelectronic devices without a significant increase in the mass–overall dimensions of microcircuits. This paper presents the results of a study of the radiation resistance of the structural, mechanical, and strength properties of synthesized CuBi2O4 films depending on the film thickness and radiation dose. Electrochemical deposition was used as a synthesis method, which allows one to control with high accuracy the phase composition and morphology of the synthesized films. Synthesized films were shown to possess a significant degree of stability to irradiation with the increasing film thickness from 5 to 10 μm. Moreover, in the case of films with a thickness of 3 μm, a decrease in the strength and structural properties is due to phase transition processes initiated by irradiation due to the transfer of energy to the crystalline subsystem as a result of elastic and inelastic collisions.

The paper presents results of helium accumulation processes in structure of the near-surface layer of WO3 microparticles as a result of irradiation with low-energy helium ions He2+ 40 keV. The dependences of changes in morphology of surface layer at irradiation, as well as the structural characteristics of microparticles at irradiation, are established. According to the data obtained, an increase in the irradiation fluence leads to the formation of cracks and fused regions in the surface layer. It was found that, at an irradiation dose of 1016 ion/cm2, the formation of disordered regions in the structure characteristic of helium inclusions is observed.

The results of the synthesis and subsequent phase transformations of FeCo nanowires depending on the annealing temperature are presented. An annealing temperature range of 200–800 °C was chosen to initialize the processes of annihilation of point defects at low temperatures, as well as phase transformations as a result of oxidation of nanostructures at high annealing temperatures. In the course of the research, a three-stage process of phase transformations was established, accompanied by oxidation of the structure followed by the formation of oxide phases of the spinel type Fe2CoO4 and Co3O4. It was found that at temperatures of 400 °C and 600 °C, the introduction of oxygen occurs nonuniformly along grain boundaries with the subsequent formation of oxide compounds, and in the case of annealing at a temperature of 800 °C, the oxygen distribution in the structure of nanowires becomes uniform, which indicates the complete oxidation of nanowires with isotropic the formation of oxide phases in the entire volume of nanowires. The prospects of using oxide biphasic nanowires for catalytic reduction reactions para-nitroaniline - para-phenyldiamine are shown.

The work is devoted to the study of the effect of electron irradiation on the ordering of the crystal structure and properties of Fe oxide nanoparticles obtained by chemical synthesis and subsequent thermal annealing. X-ray diffractometry, scanning electron microscopy, energy dispersive analysis and 57Fe Mossbauer spectroscopy were used as research methods. It was found that increasing the irradiation dose from 50 to 150 kGy leads to enlargement of particles from initial size 40 nm to 45–50 nm, while subsequent irradiation leads to the formation of ellipsoidal or rhombic particles, the average size of which is no more than 50–60 nm. Using the method of Mossbauer spectroscopy, it was found that with an increase in the irradiation dose, the relative intensity of the subspectrum of 57Fe nuclei in locally heterogeneous areas decreases from 9.7 ± 0.8% to 0.6 ± 0.6%, which indicates a significant decrease in the density of oxygen vacancies and the ordering of the crystal and magnetic structure nanoparticles. A decrease in the density of oxygen vacancies and a decrease in deformation distortions in the structure indicate the promise of using electronic irradiation to modify the properties of nanoparticles. In the course of life tests of the applicability of the studied nanoparticles as cathode materials for lithium-ion batteries, it was found that increasing the irradiation dose leads to an increase in the specific capacitance from 202 to 215–218 mA g−1, as well as a decrease in capacitance loss in case of a change in the charge/discharge rate, which indicates an increase in the stability of nanoparticles to degradation arising in the process of life tests.

This paper presents the results of studying the processes of defect formation caused by irradiation with protons with an energy of 1.5 MeV and doses of 1 × 1015, 1 × 1016, 1 × 1017 ion/cm2 in ceramics based on aluminum nitride. The choice of radiation doses is due to the possibility of modeling atomic displacement (dpa) values of 0.56, 5.6, and 56 dpa, respectively. An analysis of structural changes showed a significant stability of the crystal structure at irradiation doses comparable to 0.56, 5.6, while an increase in the displacements up to 56 dpa leads to a significant increase in distortions of the crystal structure and its disordering due to the effect of accumulation of defects in the structure, as well as to hydrogenation processes. The totality of the data obtained indicates a fairly high degree of resistance to proton irradiation and the subsequent evolution of defects in the structure of nitride ceramics; however, at high doses of radiation, microcracks form in the surface layer, which leads to a sharp deterioration in the strength properties due to a large number of dislocation and point defects.

Annotation The paper presents the results of a study of the phase composition, structural properties, and applicability of perovskite-like ceramics of the LiZrBaOx type obtained by solid-phase synthesis. According to the data of X-ray phase analysis, mapping, and TEM images, it was established that the ceramic structure consists of core-shell particles where the ZrO2 phase acts as the core, and the ZrBa2O4 and Zr2Li6O7 phases are a double shell, one of which is the disordered Zr2Li6O7 shell. The presence of three phases in the structure leads to a sufficiently strong distortion of the crystalline structure, as well as its deformation. In the course of the research, the prospects of using ceramics based on LiZrBaOx as the basis for the cathode materials of lithium-ion batteries were established.

The paper presents the results of changes in the structural and strength parameters of TiN-based thin films obtained by magnetron sputtering when irradiated with low-energy Kr14+ ions with an energy of 280 keV. As a result of studying the effect of irradiation on surface morphology, it was found that an increase in the irradiation fluence above 1013 ion/cm2 leads to the formation of large sphere-like inclusions in the structure of the surface layer, the average size of which varies from 300 to 700 nm, and the height is 50–70 nm. It was established that a change in the parameters of the crystal lattice and their c/a ratio indicates a change in interplanar spacings due to migration of defects in the structure and their agglomeration, as well as to stretching of the lattice along the c axis and a change in its volume. Based on the change in the intensities and shape of the diffraction maxima, an assumption was made about the reorientation of the texture and the change in the positions of crystallites as a result of their fragmentation or reorientation.

The paper presents the results of a study of structural characteristics, as well as the possibility of using Li0.15Sr0.85TiO3 ceramics as anode materials for lithium-ion batteries. It has been established that the structure of ceramics is an accumulation of dendritic agglomerates consisting of spherical and spherical nanoparticles with a developed specific surface. According to X-ray phase analysis, the ceramic crystal structure is a mixture of two phases: cubic SrTiO3 and orthorhombic Li2Ti3O7, with a predominance of the SrTiO3 phase. During the life tests, it was found that in the case of the 1000 mAh/g mode, the resource number of cycles is close to 480–500 cycles, which is typical for most silicon-based structures that are standardly used as the basis for lithium-ion batteries. An increase in the charging capacity to 1500 mA h/g leads to a slight decrease in the resource lifetime—420 cycles to a decrease in capacity below 80%. Based on the conducted tests of life tests, the prospects of using ceramics based on Li0.15Sr0.85TiO3 as the basis for lithium-ion batteries have been established.

The paper presents the results of a study of the influence of heavy ions Xe22+ on the morphology, phase composition, structural and conductive characteristics of CoO/Co0.65Zn0.35 nanowires obtained...

The paper presents study results of structural and optical changes in heavy ion irradiated BeO ceramics. Irradiation was carried out on DC-60 heavy ion accelerator using Ni12+ ions with an energy of 100 MeV with irradiation fluence of 1013-1014 ions/cm2. It has been established that intensity decrease and shape change of OSL (Optically Stimulated Luminescence) curves for irradiated samples are caused by concentration increase of defects and amorphous inclusions, which affect ceramics reflectance. It has been determined that change in magnitude of atom displacements from lattice sites is exponential, which has great influence on crystal structure distortion and deformation in case of defect overlap regions formation at large irradiation fluences.

This work is devoted to studying blistering in ZrN, AlN, and CrN films formed by reactive magnetron sputtering. The surface morphology and cross-sectional microstructure of mononitride films after irradiation with He ions (energy 40 keV and doses of 3 × 1017−1.1 × 1018 cm–2) at room temperature are analyzed by scanning, atomic force, and transmission electron microscopy. The critical doses of blistering are determined for ZrN (6 × 1017 cm–2), AlN (5 × 1017 cm–2), and CrN (6 × 1017 cm–2) films. The high density of blisters in ZrN films leads to the merging of neighboring blisters (average size 0.75 μm) and the formation of large blisters (average size 1.35 μm). The blisters in the AlN films have a regular round shape (average size 1.7 μm). The СrN films are characterized by the presence of open blisters having a two-level structure: an upper blister with a diameter of 2−10 μm and a lower one with a diameter of 1.2 μm. As follows from the TEM results, 40‑keV He-ion irradiation of the films and their subsequent vacuum annealing leads to the formation of chains of radiation-induced pores filled with helium in the region of the projective ion range Rp. The formation of extended cracks is found to occur in the Rp region of ZrN, which is caused by interbubble fracturing due to high excess pressure in pores located at a depth close to Rp.

The paper presents the results of a study of changes in structural and magnetic characteristics, as well as phase transformations in Fe–Ni/Fe–Ni–O nanoparticles obtained by chemical synthesis and subsequent thermal annealing. It was found that the initial nanoparticles are a three-phase system consisting of Fe–Ni–O oxide with a spinel structure and a Fe–Ni alloy with a face- and body-centered cubic lattices. As a result of thermal annealing, a decrease in the Fe–Ni phase was established with subsequent ordering of the Fe–Ni–O phase with a decrease in the crystal lattice parameter and an increase in the degree of crystallinity. During resurces tests, it was found that for single-phase Fe–Ni–O nanoparticles, the lifetime is close to 500 discharge/charge cycles, which is a good indicator of the working life and makes it promising to use Fe–Ni/Fe–Ni–O nanoparticles as anode materials for lithium-ion batteries.

The paper presents the results of a study of structural, optical and conductive properties of ferroelectric microparticles based on ATiOx (A = Ba, Ca, Sr) obtained by solid-phase synthesis. According to the data obtained, as a result of the synthesis microparticles of dendroid form were obtained. During the study, the dependences of the change in the phase composition and crystallographic characteristics on the choice of component A in the structure of a ferroelectric are established. Studies of conductive and optical characteristics of investigated microparticles were conducted. During tests of conductive characteristics of microparticles, the nonlinearity of the current – voltage characteristics was established due to the presence of impurity inclusions in the structure and a high concentration of vacancy and dislocation defects, which have a significant effect on the ballistic nature of charge transfer.

The interest in lithium-containing ceramics is due to their huge potential as blanket materials for thermonuclear reactors for the accumulation of tritium. However, an important factor in their use is the preservation of the stability of their strength and structural properties when under the influence of external factors that determine the time frame of their operation. This paper presents the results of a study that investigated the influence of the LiTiO2 phase on the increasing resistance to degradation and corrosion of Li2TiO3 ceramic when exposed to aggressive acidic media. Using the X-ray diffraction method, it was found that an increase in the concentration of LiClO4·3H2O during synthesis leads to the formation of a cubic LiTiO2 phase in the structure as a result of thermal sintering of the samples. During corrosion tests, it was found that the presence of the LiTiO2 phase leads to a decrease in the degradation rate in acidic media by 20–70%, depending on the concentration of the phase. At the same time, and in contrast to the samples of Li2TiO3 ceramics, for which the mechanisms of degradation during a long stay in aggressive media are accompanied by large mass losses, for the samples containing the LiTiO2 phase, the main degradation mechanism is pitting corrosion with the formation of pitting inclusions. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. Funding: This research was funded by the Science Committee of the Ministry of Education and Science of the Republic of Kazakhstan (No. AP08855734).

Paper presents the results of a study of the applicability of pulsed C+/H+ (85/15) beams with a high current density for directional modification and hardening of the surface layer of AlN nitride ceramics. The purpose of the modification is to increase the radiation resistance to helium embrittlement and swelling as a result of the accumulation of helium in the surface layer. It has been established that an increase in the number of processing pulses leads to a sharp change in the morphology of surface layer, as well as a change in strength characteristics of ceramics. The sharp deterioration of strength characteristics is due to the presence in the structure of the surface layer of a high density of dislocations and defects, as well as the formation of microcracks as a result of pulsed processing with a large number of pulses. The effect of modification on the change in the structural characteristics of investigated samples has been established. It should be noted that these changes occur in a small surface layer with a thickness of not more than 0.5 μm, which is most susceptible to degradation under irradiation and influence of corrosive media during practical use.

The formation of Zn-based nanotubes by electrochemical synthesis in pores of template polymer matrices is considered. It is established that the number of defects in the synthesized nanotubes decreases with a decrease in the mean crystallite size, while the degree of crystallinity increases. The number of defects directly affects the structural properties of Zn nanotubes. However, an uncontrolled growth of nanotubes is observed at a potential difference of 2.0 V, as a result of which amorphous inclusions are formed in the crystal structure of nanotubes, thus leading to their partial destruction.

The paper presents the results of a study of the formation and evolution of radiation defects under the irradiation of nuclear materials based on beryllium oxide with the heavy ions Ni12+. The irradiation with 100-MeV Ni12+ ions was carried out on a DC-60 accelerator, and the irradiation fluence was 1013–1014 ion/cm2. It has been established that the crystal lattice parameter changed insignificantly at low irradiation fluences typical of the formation of single defects. An increase in the irradiation fluence led to a sharp change in the parameter value and a root-mean-square displacement of atoms from lattice sites due to an increase in the concentration of distortions in the structure. It has been found that the magnitude of the displacements of atoms from lattice sites exponentially changed due to the occurrence of defect overlap areas at a fluence (1014 ion/cm2) with the subsequent formation of a large number of migrating defects, which lead to crystal structure distortion and deformation, because of the rupture of chemical bonds in the structure.

The paper presents results of preparation and investigation of thin films based on TiO2 using the method of magnetron sputtering. It was established that samples obtained are polycrystalline structures with a TiO2 phase, characteristic of brookite with a high degree of crystallinity and texturing. It has been established that an increase in the thickness of films from 220 to 640 and 720 nm leads to the enlargement of crystallites and a change in films density, due to processes of crystallization and nucleation during the deposition process. It is determined that an increase in coating thickness leads to an increase in hardness and strength, which is caused by a change in the crystal structure and a decrease in amorphous inclusions. It is shown that the use of TiO2-based thin films with a given thickness can significantly increase the corrosion resistance of stainless steel and reduce the rate of surface degradation.

ZnO nanoclusters obtained by electrochemical deposition (ECD) of zinc in track template a-SiO2/Si-n have been studied. The structure SiO2/Si was irradiated at DC-60 cyclotron with 200 MeV Xe ions (Φ = 108 ions/cm2) with subsequent chemical etching in the diluted hydrofluoric acid (HF). Electrochemical deposition (ECD) of Zn in track template was carried out in the potentiostatic mode. The surface of samples was examined using a SEM JSM 7500F microscope. X-ray diffraction analysis was carried out using a D8 ADVANCE ECO X-ray diffractometer. According to XRD, the electrodeposition of zinc into the a-SiO2/Si-n track template resulted in a formation of zincblende (ZB) ZnO nanocrystals. Current-voltage characteristics and photoluminescence of SiO2/Si track template with ZnO ZB nanocrystals were investigated.

The paper presents the results of studying of structural and phase properties of films based on copper–bismuth, copper–magnesium, copper–nickel, obtained by the method of electrochemical deposition. The dependences of the influence of the synthesis conditions on the phase composition and the strength and corrosion properties of the synthesized films are established. Interest in two-component films based on selected metals is due to their structural properties and the prospect of using them as protective coatings. The choice of elements of bismuth, magnesium and nickel in combination with copper is due to the possibility of obtaining structures with different phases, which can have a significant impact on the corrosion properties of films when interacting with aggressive media. During tests for corrosion resistance, it was found that a decrease in the concentration of copper and copper-containing phases leads to an increase in resistance to degradation and oxidation of thin films.

The paper presents results of studies on defect formation processes, radiation resistance, amd changes in the conductive and insulating characteristics of AlN ceramics under irradiation with 40 keV He2+ ions. The radiation fluence ranged from 1015 to 5 × 1017 ion/cm2. Using the method of X-ray structural analysis, it has been established that an increase in the irradiation fluence leads to a decrease in intensities of diffraction peaks and a change in lines shape, which indicates an increase in the concentration of distortions and stresses in the crystal structure. The change in concentration of deformation in the structure is due to the increase in the content of introduced helium and the formation of cascades of secondary defects and vacancies. At large fluences of irradiation (above 1017 ions/cm2), diffraction patterns show the formation of a halo characteristic of X-ray amorphous or highly disordered impurity inclusions and the formation of spherical inclusions in the surface layer, the average size of which varies from 50 to 100 nm. The decrease in resistance and thermal conductivity as a result of irradiation and the formation of helium inclusions in the structure indicates a degradation of the structural characteristics, as well as a decrease in radiation resistance, which is caused by a drop in strength characteristics.

The paper presents results of studying the effect of irradiation of low-energy helium ions on structural properties and morphology of AlN polycrystalline ceramics. On the basis of X-ray diffraction patterns, dependences of the change in stresses in the structures of types I and II, as well as the magnitude of atoms displacements from lattice sites as a result of irradiation, were determined. According to the data obtained, with small irradiation fluences, characteristic of a low concentration of implanted helium ions and defects in the structure, the change in the magnitude of displacements and stresses is insignificant. An increase in fluence above 1017 ion/cm2 leads to a drastic change in distortions and deformations in the structure, as well as to an increase in the value of rms displacement of atoms from the lattice sites. It has been established that the greatest decrease in microhardness and resistance to stress is observed for samples irradiated with fluences above 1017 ions/cm2, which are characterized by the formation of a large concentration of defects and impurity inclusions. The decrease in microhardness is due to the formation of regions of disorder and helium bubbles, as well as a decrease in the density of ceramics and the degree of crystallinity.

The paper presents the results of the synthesis and studies of changes in the phase composition, structural and magnetic properties of double perovskites Ce(FeTi)Ox obtained by solid-phase synthesis. To assess the effect of changes in physical-chemical and magnetic properties in synthesis and subsequent thermal annealing, we used the methods of scanning electron microscopy, energy dispersive and X-ray phase analysis, Mossbauer spectroscopy. It is established that the synthesized samples are a mixture of five phases, characteristic of compounds of cerium with iron and cerium with titanium. A change in the concentration of phases in the annealing process indicates phase transformations and a change in the main crystallographic characteristics. It is established that a decrease in the concentration of oxygen ions in the crystal structure, caused by thermal processes, leads to an increase in the density of oxide phases and the formation of magnetic ordering in the structure.

This paper presents the results of the structural, corrosion, magnetic properties and cytotoxicity of magnetite nanoparticles, phase transformations was studied by thermal annealing. It was established that thermal annealing of Fe3O4 nanoparticles led to three stages of phase transformations from magnetite to maghemite, with the subsequent formation of the hematite structure. Increasing annealing temperature lead to a change in the magnitudes of the hyperfine magnetic field, quadrupole displacement and isomeric shift that indicates a change in the crystal structure and annealing of defects, which eventually leads to the ordering of magnetic nanoparticles. Studying the degradation of nanoparticles in PBS solution shows us that a change in the crystal structure as a result of a decrease in the degree of perfection and the formation of amorphous inclusions leads to magnetic disordering and a subsequent change in the magnitude of the hyperfine magnetic field. Cytotoxicity results indicate that nanoparticles do not show cytotoxic activity against tested L929, PC-3 and HeLa cell lines, because in all experimental series metabolic activity of studies cells was not below 70% of control.

The work presents the changes in the structural and conductive properties of Ni nanostructures. B2+, Ca5+, Fe7+ ions were used as the bombarding beams. Fluence irradiation constitutes 1010, 1011 и 5 × 1011 ion/cm2. The use of ions B2+, Ca5+, Fe7+ allows to simulate the effects of irradiation with different energy losses, as well as the course of the process of defects formation in structures. It has been established that in the samples irradiated with B2+ and Ca5+ ions, the main structural changes are associated with amorphization or texture reorientation, and for samples irradiated with Fe7+ ions, the formation of low intense peaks characteristic of FeNi is observed. It has been established that an increase in the degree of crystallinity indicates a positive effect of calcium ions on the crystal structure, which consists in the partial annealing of defects and the removal of stresses and distortions in the crystal lattice. A slight decrease in the degree of crystallinity during irradiation with iron ions can be explained by the processes of implantation and knocking out of nickel atoms from lattice sites, which leads to the formation of impurity inclusions in the form of the FeNi phase, the content of which increases with irradiation fluence. The formation in the structure of amorphous inclusions and partial destruction of the walls of nanotubes under the action of irradiation with boron ions leads to a sharp decrease in the degree of crystallinity and conductive properties of nanotubes.

The paper presents the results of a study of the radiation resistance of ceramic materials based on aluminum nitride. The irradiation was carried out by C2+ ions with an energy of 40 keV with a fluence from 1014 to 1015 ion/cm2 at an irradiation temperature of 300 K. On the basis of the data obtained by the XRD, SEM, EDX methods, the dependence of the change in crystallographic characteristics and strength properties from the irradiation dose was established. It is established that as a result of irradiation of the near-surface layer, formation of an impurity phase of Al4C3 is observed, which leads to an increase in parameters of the crystal lattice, which indicates the implantation of C2+ ions and the formation of the implantation phase in the structure. In this case, an increase in contributions of the impurity phases leads to a decrease in the intensity of diffraction peaks, as well as their asymmetry, which is caused by an increase in microstresses and deformations in the lattice. The decrease in hardness and strength characteristics can be explained by the formation of regions of structure disorder in the near-surface layer, as well as the increase in material porosity due to the change in density.

The paper presents the results of a study of the effect of proton and ion radiation on structural changes in nitride ceramics, which have a high potential for using as a structural material for GenIV nuclear reactors. Proton beams with an energy of 1.5 MeV and low-energy helium (He2+) and carbon (C2+) ions with an energy of 40 keV were used, to simulate defect formation and to estimate ceramics radiation resistance. According to the data obtained, it has been established that aluminum nitride ceramics have high radiation resistance to the effects of proton radiation. While under irradiation with C2+ ions, the observed degradation of the surface layer is due to the accumulation of carbon in the structure with the subsequent formation of impurity carbide inclusions. It is established that the accumulation of slightly soluble ions of helium and carbon in the structure of the surface layer leads to an increase in the strain and distortion of crystal lattice due to introducing ions into the interstitial lattice and breaking chemical and crystalline bonds. As a result of studying the optical characteristics of irradiated samples, it was found that the decrease in absorption spectra intensity for samples irradiated with helium and carbon ions is due to a change in the interplanar distances as a result of the migration of defects along the structure with the subsequent formation of impurity inclusions. The formation of impurity phases and a high concentration of defects in the structure of ceramics leads to a sharp decrease in performance.

The effect of irradiation with C2+ ions on changes in optical and structural properties of AlN-based ceramics has been studied. The choice of C2+ ions is due to the possibility of modeling defects formation in the surface layers, as well as the formation of carbide phases in the structure during irradiation. According to XRD data, the formation of an impurity phase characteristic of the Rhombohedral Al4C3 is observed in the structure of irradiated samples, the presence of which is due to the implantation of carbon ions into the surface layers of not more than 150 nm. The decrease in the intensity of the TSL spectrum for irradiated samples is due to the appearance of defects, as well as an increase in the concentration of impurity atoms. That leads to the substitution of Al and N atoms in the structure. At the irradiation dose of 1015 ion/cm2, there is a sharp increase in the absorption spectrum and the magnitude of the optical absorption.

The study of changes in physical-chemical and mechanical properties of ceramic nitride materials as a result of the effect of heavy ions is of great interest in the field of radiation-resistant materials. In the course of investigation conducted there has been determined the mechanisms of ionizing irradiation effect on change of the main crystallographic characteristics and performance characteristics of nitride ceramics (reduction of thermal conductivity, strength, electrical resistivity and microhardness). The choice of Fe7+ ions with energy of 85 MeV is due to possibility of modeling by using it a fission fragments in reactors. In turn, the determination of mechanisms of change of structural properties and radiation resistance of materials is an important factor in the study of radiation damage in materials for nuclear industry. It has been proved that when the density of ceramics decreases due to a change in the crystallographic characteristics, the conducting properties decrease and the resistance of ceramics to the formation of microcracks decreases. The application of the ATR-FTIR method allowed to examine the change in chemical bonds in the near-surface irradiated layer as a result of irradiation. In addition, the effect of various factors in the variation of diffraction peaks has been evaluated using the Williamson-Hall method, which evidences that at small doses the contributions from size effects and deformation of the structure due to stresses are equivalent. An increase in the irradiation dose up to 1 × 1013 ion/cm2 and higher, the greatest contribution to the change in the structural properties was due to the deformations of the crystal lattice, which are caused by the formation of a large concentration of regions with a high density of defects and oxide impurities in the crystal structure.

By template synthesis method nickel nanotubes with diameter of 400 nm and length of 12 μm were produced in the pores of PET template. The nanotubes were modified by irradiation with carbon ions with energy of 28 MeV and a dose of 5 × 1011 cm-2. To ensure the maximum efficiency of nanostructures modification process, energy of irradiation was decided by using of SRIM software. Based on SRIM simulation of carbon ions interaction with Ni nanotubes, the areas on which effect of high energy ions will maximum were predicted. A comparative analysis of nanostructures before and after irradiation was carried out by scanning electron microscopy. The maximum change in nanotubes morphology, in the form of destruction of walls, was appeared at a distance of about 10 μm from the start point of C3+ ions track inside the nanotubes. A substantiation of reason of wall degradation in this area was proposed. © 2019 Elsevier Ltd. Horizon 2020 Framework Programme, H2020: 778308.

The paper presents the results of studying the effect of irradiation of Fe7+ ions with an energy of 1.5 MeV/nucleon on structural properties of AlN ceramics at an irradiation temperature of 300, 500, 700 and 1000 K. The choice of ion type and irradiation conditions was made by studying the processes of defect formation as a result of particles effect with energies close to fission fragments of nuclear fuel (≤90–100 MeV) and temperatures 0.1–0.3 Tmelt, typical for annealing defects. From the data obtained by the XRD, SEM, EDX methods, it is established that an increase in irradiation temperature above 500 K leads to a reduction in distortions and deformation of the crystal lattice under irradiation. It was found that with an increase in the irradiation dose, amorphous-like grains with a high oxygen content are formed in the structure, which are characteristic for the impurity phase of Al2O3, the content of which in the ceramic structure does not exceed 5%. In this case, an increase in the irradiation temperature leads to a decrease in impurity phase concentration in the structure. It has been established that for samples irradiated at high temperatures 700–1000 K, the decrease in strength properties is less than for samples irradiated at a temperature of 300 and 500 K. Such a difference can be explained by partial annealing and annihilation of defects as a result of elevated temperatures. The decrease in thermal conductivity coefficient in irradiated samples is due to an increase in defects concentration in structure, as well as a decrease in their mobility.

For the first time the possibility of synthesizing of an optical ceramics MgF2 using a powerful electron beam as a heater is shown. In the process of synthesis, the charges consisting of magnesium fluoride powder with different ratio between the dopants WO3 and LiOH were exposed to an electron beam with 1.4 MeV electron energy and power of 18 kW on an area of 1 cm2. Investigations of the elemental composition and structure of the synthesized ceramics showed the presence of crystalline phases MgF2, W, WO3, and Mg in the samples. The size of the crystalline grains and efficiency of their formation depend on the composition of the charge. It was found that the synthesized ceramics samples luminesce in the 470 nm region at 300 K. Excitation spectrum of this emission in ceramics consists of two bands with maxima at 250 nm and about 200 nm. The spectral properties of MgF2 ceramics in general are similar to those in ZnWO4 single crystals and LiF crystals doped with tungsten oxide.

Analytic expressions for the low-field mobility have been obtained in black phosphorus crystals and multilayer phosphorene. Acoustic and optical phonons, charged impurities and surface roughness are adopted as the scattering system. Theoretical considerations are based on a quantum kinetic equation and special form of the non-equilibrium distribution function (shifted Fermi distribution). Our calculations reveal that the hole mobility in black phosphorus crystals is limited by scattering with both acoustic and optical phonons over a wide temperature range of 10–400 K. The hole mobility in multilayer phosphorene is thus limited by impurity and optical phonon scattering in this temperature range.

The effect of microstructure on the efficiency of shielding or shunting of the magnetic flux by permalloy shields was investigated in the present work. For this purpose, the FeNi shielding coatings with different grain structures were obtained using stationary and pulsed electrodeposi-tion. The coatings’ composition, crystal structure, surface microstructure, magnetic domain struc-ture, and shielding efficiency were studied. It has been shown that coatings with 0.2–0.6 µm grains have a disordered domain structure. Consequently, a higher value of the shielding efficiency was achieved, but the working range was too limited. The reason for this is probably the hindered movement of the domain boundaries. Samples with nanosized grains have an ordered two-domain magnetic structure with a permissible partial transition to a superparamagnetic state in regions with a grain size of less than 100 nm. The ordered magnetic structure, the small size of the domain, and the coexistence of ferromagnetic and superparamagnetic regions, although they reduce the maxi-mum value of the shielding efficiency, significantly expand the working range in the nanostruc-tured permalloy shielding coatings. As a result, a dependence between the grain and domain structure and the efficiency of magnetostatic shielding was found. © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This research was funded by the European Union?s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant number 861145. And The APC was funded by the European Union?s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement no. 861145.