Ion Irradiation Research Articles

First experimental verification of prompt gamma imaging with carbon ion irradiation

Prompt Gamma Imaging (PGI) is a promising technique for range verification in Particle Therapy. This technique was already tested in clinical environment with a knife-edge-collimator camera for proton treatments but remains relatively unexplored for Carbon Ion Radiation Therapy (CIRT). Previous FLUKA simulations suggested that PG profile shifts could be detected in CIRT with a precision of \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim$$\\end{document} 4 mm (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$2 \\sigma$$\\end{document}) for a particle statistic equal to \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$5 \\cdot 10^{7}$$\\end{document} C-ions using a 10 × 10 cm2 camera. An experimental campaign was carried out at CNAO (Pavia, Italy) to verify these results, using a knife-edge-collimator camera prototype based on a 5 × 5 cm2 pixelated LYSO crystal. PG profiles were measured irradiating a plastic phantom with a C-ion pencil beam at clinical energies and intensities, also moving the detector to extend the FOV to 13 × 5 cm2. The prototype detected Bragg-peak shifts with \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim$$\\end{document} 4 mm precision for a statistic of \\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\sim 4 \\cdot 10^{8}$$\\end{document} C-ions (\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$3 \\cdot 10^{8}$$\\end{document} for the extended FOV), slightly larger than expected. Nevertheless, the detector demonstrated significant potential for verifying the precision in dose delivery following a treatment fraction, which remains fundamental in the clinical environment. For the first time to our knowledge, range verification based on PGI was applied to a C-ion beam at clinical energy and intensities.

Enhanced NO2 Gas Sensing in Nanocrystalline MoS2 via Swift Heavy Ion Irradiation: An Experimental and DFT Study.

Nanostructured transition metal dichalcogenides (TMDs) like MoS2 hold promise for gas sensing applications due to their exceptional properties. However, limitations exist in maximizing sensor performance, such as limited active sites for gas interaction and sluggish response/recovery times. This study explores swift heavy ion (SHI) irradiation as a strategy to address these challenges in MoS2-based NO2 gas sensors. MoS2 nanoflakes were fabricated and subsequently irradiated with 120 MeV silver (Ag) ions to induce structural and morphological modifications. Characterization techniques confirmed the formation of Mo and S vacancies within the MoS2 lattice due to irradiation. Significantly, SHI irradiation resulted in a remarkable enhancement of approximately 3 times improvement in sensing response compared to pristine MoS2 sensors. Additionally, the irradiated sensors exhibit substantial improvements in both response and recovery times for NO2 detection. SHI irradiation resulted in the formation of self-affine nanostructures and increased grain fragmentation as fluence rises. This enhanced surface area is hypothesized to promote gas-sensor response. To gain deeper insights into the underlying mechanism, first-principles calculations were employed. These calculations suggest that electron transfer occurs from the MoS2 surface to the NO2 molecule during interaction. Furthermore, the irradiation-induced vacancies facilitate stronger NO2 adsorption on the MoS2 surface compared to the pristine sample. This work demonstrates the effectiveness of SHI irradiation in engineering defects within MoS2 nanoflakes, leading to significantly improved NO2 gas-sensing performance. This approach offers a promising avenue for developing next-generation TMD-based gas sensors with enhanced sensitivity, response times, and stability.

Temperature dependence of irradiation-induced amorphization in a high-entropy titanate pyrochlore

AbstractThe temperature dependence of amorphization in a high-entropy pyrochlore, (Yb0.2Tm0.2Lu0.2Ho0.2Er0.2)2Ti2O7, under irradiation with 600 keV Xe ions has been studied using in situ transmission electron microscopy (TEM). The critical amorphization dose increases with temperature, and the critical temperature for amorphization is 800 K. At room temperature, the critical amorphization dose is larger than that previously determined for this pyrochlore under bulk-like 4 MeV Au ion irradiation but is similar to the critical doses determined in two other high-entropy titanate pyrochlores under 800 keV Kr ion irradiation using in situ TEM, which is consistent with reported behavior in simple rare-earth titanate pyrochlores. Graphical abstract

The Induction of Drug Uptake Transporter Organic Anion Transporting Polypeptide 1A2 by Radiation Is Mediated by the Nonreceptor Tyrosine Kinase v-YES-1 Yamaguchi Sarcoma Viral Oncogene Homolog 1.

Organic anion transporting polypeptides (OATP, gene symbol SLCO) are well-recognized key determinants for the absorption, distribution, and excretion of a wide spectrum of endogenous and exogenous compounds including many antineoplastic agents. It was therefore proposed as a potential drug target for cancer therapy. In our previous study, it was found that low-dose X-ray and carbon ion irradiation both upregulated the expression of OATP family member OATP1A2 and in turn, led to a more dramatic killing effect when cancer cells were cotreated with antitumor drugs such as methotrexate. In the present study, the underlying mechanism of the phenomenon was explored in breast cancer cell line MCF-7. It was found that the nonreceptor tyrosine kinase v-YES-1 Yamaguchi sarcoma viral oncogene homolog 1 (YES-1) was temporally coordinated with the change of OATP1A2 after irradiation. The overexpression of YES-1 significantly increased OATP1A2 both at the mRNA and protein level. The signal transducer and activator of transcription 3 (STAT3) pathway is likely the downstream target of YES-1 because phosphorylation and nuclear accumulation of STAT3 were both enhanced after overexpressing YES-1 in MCF-7 cells. Further investigation revealed that there are two possible binding sites of STAT3 localized at the upstream sequence of SLCO1A2, the encoding gene of OATP1A2. Electrophoretic mobility shift assay and chromatin immunoprecipitation analysis suggested that these two sites bound to STAT3 specifically and the overexpression of YES-1 significantly increased the association of the transcription factor with the putative binding sites. Finally, inhibition or knockdown of YES-1 attenuated the induction effect of radiation on the expression of OATP1A2. SIGNIFICANCE STATEMENT: The present study found that the effect of X-rays on v-YES-1 Yamaguchi sarcoma viral oncogene homolog 1 (YES-1) and organic anion transporting polypeptides (OATP)1A2 was temporally coordinated. YES-1 phosphorylates and increases the nuclear accumulation of signal transducer and activator of transcription 3, which in turn binds to the upstream regulatory sequences of SLCO1A2, the coding gene for OATP1A2. Hence, inhibitors of YES-1 may suppress the radiation induction effect on OATP1A2.

Modification of the Surface Topography of Additive Materials under Ar+ Ion Irradiation

Additive manufacturing (AM) is a modern developing group of technologies based not on the removal of material, but on the layer-by-layer growth and synthesis of an object according to a CAD (Computer-Aided Design) model. The main disadvantages of objects manufactured using AM technologies are a high degree of porosity and surface roughness. This work examines the possibility of modifying the surface of additive materials Ti6Al4V and AlSi10Mg using irradiation with Ar+ ions with energies in the range from 2 to 9 keV. Using SEM, the surface topography was obtained before and after irradiation and mechanical polishing. A reduction in surface porosity and roughness was demonstrated, as well as the influence of beam energy on the final surface topography.

The mechanism of degradation and failure in NiO/ β -Ga2O3 heterojunction diodes induced by the high-energy ion irradiation

This work investigated the single-event effects (SEE) of NiO/β-Ga2O3 heterojunction diodes (HJDs) irradiated by 1.86 GeV tantalum ions with linear energy transfer over 80 MeV cm2/mg. The HJDs exhibited radiation responses with the early single-event leakage current (SELC) degradation until the fatal single-event burnout (SEB) failure, which was far below their breakdown voltages. Meanwhile, the surface morphology revealed the SELC damage expressed as burnout of topside NiO and metal stacks, while the SEB damage was observed as a burned hole in the β-Ga2O3 epitaxial layer. According to technology computer aided design simulations, the thicker p-type region in HJDs could further alleviate the electric field crowding effect exacerbated by the heavy-ion strike because of the extension of charge distribution in the p-type region. The SEB threshold was raised to 250 V by thickening the NiO layer to 300 nm. As for the SELC degradation process along with the burnout of topside stacks in HJDs, we supposed the probable reason was the intolerance of NiO to the high electric field under the SEE. This paper analyzed the SEE mechanism in β-Ga2O3 diodes and paved the way for heavy-ion irradiation hardening.

Influence of temperature gradients on helium diffusion and clustering in tungsten: A molecular dynamics study

Tungsten and its alloys, used as plasma-facing materials in fusion reactors, endure high-flux, low-energy helium ion irradiation and temperature gradients induced by thermal load and shocks. This study utilizes molecular dynamics (MD) simulations to explore the diffusion and clustering behavior of helium (He) in tungsten (W) under temperature gradients. The migration behavior of isolated helium atoms, small helium clusters, and helium self-interstitial atom (He-SIA) clusters within tungsten is analyzed. It is revealed that both helium and He-SIA clusters tend to migrate towards higher temperature regions, exhibiting negative thermophoresis. The nucleation of helium clusters, the formation of Frenkel pairs, and the interactions between self-interstitial clusters and helium clusters are also investigated. The results indicate that helium concentration significantly impacts He nucleation behavior. Directional diffusion may lead to areas of high concentration over time, potentially promoting the formation of He clusters and bubbles. These insights enhance the understanding of tungsten's performance and durability as a plasma-facing component in fusion reactors.

Modification of microstructural, mechanical and optical properties with carbon ion irradiation in Y2SiO5 crystals

Yttrium orthosilicate Y2SiO5 crystals, a member of the silicate family, are versatile and multifunctional materials when doped with rare earth or transition metal ions. However, there have been limited investigations into the impact of ion irradiation on the crystal structure of Y2SiO5 crystals to date. In this paper, the effect of microstructure, mechanical and optical properties of Y2SiO5 crystal before and after different fluences of carbon ions irradiation was investigated utilizing complementary characterization techniques. The results indicate that carbon ion irradiation caused lattice disorder and damage, which resulted in structural deterioration and changes in optical properties, such as decrease in the optical band gap energy (from5.77 eV to 5.44 eV), changes in the effective refractive index (neff) which resulted in the formation of “well + barrier” type and “barrier” type waveguides. In addition, elastic modulus increased after carbon ion irradiation. The results will be helpful for understanding the damage study of the Y2SiO5 crystal with carbon ion irradiation and proving that ion beam techniques can be used for material modification.

Microstructure Evolution of the Interface in SiCf/TiC-Ti3SiC2 Composite under Sequential Xe-He-H Ion Irradiation and Annealing Process.

A new type of SiCf/TiC-Ti3SiC2 composite was prepared by the Spark Plasma Sintering (SPS) method in this work. The phase transformation and interface cracking of this composite under ion irradiation (single Xe, Xe + He, and Xe + He + H ions) and subsequent annealing were analyzed using transmission electron microscopy (TEM), mainly focusing on the interface regions. Xe ion irradiation resulted in the formation of high-density stacking faults in the TiC coatings and the complete amorphization of SiC fibers. The implanted H ions exacerbated interface coarsening. After annealing at 900 °C for 2 h, the interface in the Xe + He + H ion-irradiated samples was seriously damaged, resulting in the formation of large bubbles and cracks. This damage occurred because the H atoms reduced the surface free energy, thereby promoting the nucleation and growth of bubbles. Due to the absorption effect of the SiCf/TiC interface on defects, the SiC fiber areas near the interface recovered back to the initial nano-polycrystalline structure after annealing.

Recrystallization of amorphous AlNbCr coatings irradiated with chromium ions

Applying an AlNbCr layer on the surface of Zr alloys significantly enhances the alloy resistance to oxidation and high-temperature corrosion. However, the effects of irradiation on AlNbCr coating remain largely unexplored. This work investigates the microstructural evolution of Cr ion-irradiated AlNbCr coatings under varying temperatures, utilizing bright-field transmission electron microscopy (TEM) observations and electron diffraction pattern analyses. With increasing Cr ion irradiation dose, the coatings gradually transitioned from an initial amorphous to a crystalline state. The onset of crystallization occurred earlier at higher temperatures, indicating that the crystallization process was significantly influenced by temperature. Moreover, the dynamic crystallization process of the crystalline structure was also analyzed, as well as the different irradiation responses at the Near-Interface Area (NIA) and Far-Interface Area (FIA). These findings provide new insights for understanding and optimizing the performance of AlNbCr coatings in high-irradiation environments.

Sampling Confined Fission Tracks for Constraining Geological Thermal Histories

Fission-track modeling rests on etching, counting and measuring the lattice damage trails from uranium fission. The tools for interpreting fission-track data are advanced but the results are never better than the data. Confined-track samples must be an adequate size for statistical analysis, representative of the track population and consistent with the model assumptions and with the calibration data. Geometrical and measurement biases are understood and can be dealt with up to a point. However, the interrelated issues of etching protocol and track selection are more difficult to untangle. Our investigation favors a two-step protocol. The duration of the first step is inversely proportional to the apatite etch rate so that different apatites etch to the same Dpar. A long immersion reveals many more confined tracks, terminated by basal and prism faces. This allows consistent length measurements and permits orienting each track relative to the c-axis. Long immersion times combined with deep ion irradiation reveal confined tracks deep inside the grains. Provided it is long enough, the precise immersion time is not important if the effective etch times of the selected tracks are calculated from their measured widths. Then, whether the sample is mono- or multi-compositional, we can, post hoc, select tracks with the desired properties. The second part of the protocol has to do with the fact that fossil tracks in geological samples appear to be under-etched compared to induced tracks etched under the same conditions. This should be assumed if the semi-axes of a fitted ellipse plot above the induced-track line. In that case, an additional etch can increase the track lengths to a point where they are consistent with the model based on lab-annealing of induced tracks, a condition for valid thermal histories. Here too, it is possible to select a subset of tracks with effective etch times consistent with the model if the widths of confined tracks are measured along with their lengths and orientations.

Radiation influence on planar reconfigurable field effect transistor low noise amplifier performance

Abstract Many novel devices have been proposed in the literature to mitigate the short channel effect and the reconfigurable FET (RFET) is one of them. The circuits based on new devices need to be investigated when they are introduced. This work has two parts: (i) designing cascoded RFET low noise amplifiers (LNA) and their performance analysis; and (ii) single-event performance analysis of RFET-LNAs. The designed LNA has a gain of 12 dB and a noise figure of 2.42 dB. The device in the common gate configuration mode is more susceptible to heavy ion radiation and collects more charge (QC) compared to the device in the common source configuration mode. Through temporal and frequency analysis, the irradiation disturbance is examined. In the temporal analysis, the collected charge (QC) is used as a metric, and the spectrogram is used in the frequency analysis.

Co-evolution of M23C6 precipitates and cavities in a boron-free Ni-based alloy GH3617 under high-temperature He ion irradiation: Effects on cavity swelling and mechanical properties

Ni-based alloys are promising materials for advanced nuclear reactors operating at high temperatures due to their exceptional resistance to high temperatures and corrosion. Understanding the synergy of phase stability and helium effects is crucial for assessing the long-term performance and reliability of these alloys in advanced nuclear reactors. This study has investigated the co-evolution behavior of M23C6 precipitates and cavities in a boron-free solid solution strengthened Ni-based alloy GH3617 under high-temperature He ion irradiation, and its impact on alloy swelling and mechanical properties, by He ion irradiation experiments with the highest fluence of 1 × 1017 He/cm2 up to 800 °C. Transmission Electron Microscopy (TEM) and Nanoindentation are employed to investigate microstructural evolution and mechanical properties, respectively. The findings show that at room temperature and 500 °C, cavities and dislocation loops were the dominant irradiation defects, whereas at 800 °C, the density of cavities and dislocations reduced while the formation of M23C6 precipitates increased. These precipitates act as effective trapping sites for He and point defect, leading to cavity formation at the interfaces or within the precipitates. Moreover, increased irradiation fluence accelerates the co-evolution process, resulting in an increase in the density and size of both precipitates and cavities, ultimately leading to enhanced swelling. The {111} planes are favored interfaces between intragranular M23C6 precipitates and the matrix due to their minimal misfit, while the preferred interface planes between cavities with octahedral or cubo-octahedral shapes and the precipitate/matrix are also {111}, owing to their lower surface energy as well. The co-evolution of cavities and precipitates was found to influence mechanical properties, resulting in an irradiation hardening effect at lower fluences, while softening at higher fluences. This study provides novel insights into the degradation mechanisms of Ni-based alloys under coupling effect of He and high-temperature irradiation.

Microstructural changes and irradiation hardening behavior of V-4Cr-4Ti alloys irradiated with He ions using flash-electropolishing

The flash-electropolishing of focused ion beam samples for V-4Cr-4Ti alloys is established, and the microstructures of high-purity V-4Cr-4Ti alloys after He ion irradiation are examined by transmission electron microscopy from room temperature to 700 °C. The correlation between irradiation hardening behavior and microstructural changes is clarified. During room temperature irradiation, defect clusters are formed at shallow positions in the specimens and no He bubbles are observed at the damage peak position. In contrast, 500 and 700 °C, TiCON precipitates are predominantly formed and He bubbles and voids were formed at the damage peak position. The results of nanoindentation tests and a comparison of irradiation hardening by irradiation damage indicate that the obstacle barrier strength factorαof TiCON is 0.45 while that of the irradiation defect clusters irradiated at room temperature is 0.10. Irradiation damage in the He ion range extends toward the interior of the specimens with increasing irradiation temperature.

Effects of High-Linear-Energy-Transfer Heavy Ion Radiation on Intestinal Stem Cells: Implications for Gut Health and Tumorigenesis.

Heavy ion radiation, prevalent in outer space and relevant for radiotherapy, is densely ionizing and poses a risk to intestinal stem cells (ISCs), which are vital for maintaining intestinal homeostasis. Earlier studies have shown that heavy-ion radiation can cause chronic oxidative stress, persistent DNA damage, cellular senescence, and the development of a senescence-associated secretory phenotype (SASP) in mouse intestinal mucosa. However, the specific impact on different cell types, particularly Lgr5+ intestinal stem cells (ISCs), which are crucial for maintaining cellular homeostasis, GI function, and tumor initiation under genomic stress, remains understudied. Using an ISCs-relevant mouse model (Lgr5+ mice) and its GI tumor surrogate (Lgr5+Apc1638N/+ mice), we investigated ISCs-specific molecular alterations after high-LET radiation exposure. Tissue sections were assessed for senescence and SASP signaling at 2, 5 and 12 months post-exposure. Lgr5+ cells exhibited significantly greater oxidative stress following 28Si irradiation compared to γ-ray or controls. Both Lgr5+ cells and Paneth cells showed signs of senescence and developed a senescence-associated secretory phenotype (SASP) after 28Si exposure. Moreover, gene expression of pro-inflammatory and pro-growth SASP factors remained persistently elevated for up to a year post-28Si irradiation. Additionally, p38 MAPK and NF-κB signaling pathways, which are critical for stress responses and inflammation, were also upregulated after 28Si radiation. Transcripts involved in nutrient absorption and barrier function were also altered following irradiation. In Lgr5+Apc1638N/+ mice, tumor incidence was significantly higher in those exposed to 28Si radiation compared to the spontaneous tumorigenesis observed in control mice. Our results indicate that high-LET 28Si exposure induces persistent DNA damage, oxidative stress, senescence, and SASP in Lgr5+ ISCs, potentially predisposing astronauts to altered nutrient absorption, barrier function, and GI carcinogenesis during and after a long-duration outer space mission.

Effect of stress and irradiation fluence on latent track formation in swift heavy ion irradiation: A case study on TiO2

Swift Heavy Ions (SHI) irradiation, characterized by high kinetic energy ions, induces significant material/structural modification, e.g., latent track. However, the intricate interaction among various physics, i.e., mechanical stress, phase transition, and heat transfer, has been ignored in the continuum-based approaches in favor of simplicity. Here, we developed a two-dimensional coupled phase-field inelastic-thermal spike (PF-iTS) model to investigate the effect of thermal cross-talk, elastic energy, and irradiation fluence on latent track formation and size. The results reveal a shift in the critical electronic stopping energy and a reduced track radius under mechanical stress. Additionally, the study demonstrates the impact of thermal cross-talk between incidents, i.e., simultaneous and delayed double ion impacts, showing potential track merging and variations in track morphology.

Full-scale modeling and experimental study of a gas neutron tube with a Penning ion source

This paper studies full-scale gas neutron tube modeling, including the following processes: gas discharge combustion in a Penning ion source, particle motion in an ion optical system, and modeling the in-target processes, such as sputtering, diffusion, thermal desorption of hydrogen isotopes, and nuclear reactions. Plasma modeling in quadrupole electric and axial magnetic fields was based on the electrostatic particle-in-cell method with molecular kinetic processes. The TechX Vsim software package was used. The neutron tube element sputtering by ions was simulated using SRIM/TRIM software based on Monte–Carlo methods. The OpenFOAM, as an open integrated platform for numerical simulation in continuum mechanics, was used to calculate the hydrogen thermal desorption activated by ion irradiation. The time-dependent neutron yield modeling was performed using the Geant4 software based on Monte–Carlo methods with CHIPS-TPT VNIIA-developed library. In addition, an experimental study of a gas neutron tube with a Penning ion source was conducted here as well. Details are given on the experiment and measurement technique used in this study. The operating characteristics for the gas neutron tube, including amplitude-time characteristics of current flashes (discharge and extraction currents), were determined. The neutron flux dependencies on the discharge current at various accelerating voltages were also obtained. Finally, a comparison between the experimental and calculated results is presented.

Development of nano-porous Au thin film at room temperature via ion irradiation in a-Ge/Au bilayer system followed by chemical etching of Ge

The development of nano-porous gold (NPG) via room temperature ion irradiation has been presented in detail. The bilayer thin films of a-Ge/c-Au have been irradiated by 100 MeV Ni ions with the fluence of 5 × 1013 ions cm−2 at room temperature. NPG is obtained by selectively etching Ge off from the Au matrix by dipping the Ge/Au thin film into 10 % H2O2 solution. Diffusion of Ge and Au across the interface under irradiation was confirmed by TRIM simulation and RBS spectra. The SEM image and EDX spectra confirms the formation of NPG with high purity. In addition, the statistical and fractal analysis of AFM image also confirms the formation of NPG. NPG system has been observed to show very good optical properties (low reflectance and high transmittance). The high quality NPG prepared by this method can be useful in the fields like optical sensors, transparent conductive electrodes, anti-reflective coatings, and photo-detector technology.

The influence of structural defects on the electrical and infrared emission properties of VO2 thin films

Defect engineering is widely used in the modification of transition metal oxides. In this study, defects are introduced into the polycrystalline VO2 film by the energetic Ar ion irradiation, and the influence of structural defects on the electrical and infrared emission properties of VO2 thin films have been investigated. The decrease in electrical switching ratio with the increase of defect ratio (displacement per atom (dpa)) can be described as R10°C/R90°C=2.032×(dpa+0.005)−1.8069, while the infrared modulation performance is Δε=−0.119×ln(dpa+0.061). The dpa thresholds of the electrical switching ratio and the infrared modulation performance are ηdpaRR = 0.005/atom and ηdpaΔε = 0.0426/atom, respectively, indicating that the electrical switching ratio of VO2 films is more responsive to defects than the infrared modulation performance. The relationship between transition temperature and defect ratio has be determined. Concerning electrical properties, the heating phase transition temperature can be described as TMITHeating=25.88−10.93×ln(dpa+0.01); while for infrared emission modulation, the heating phase transition temperature is given by Tε−MITHeating=31.65−8.18×ln(dpa+0.01). While reducing the phase transition temperature, the VO2 thin films still exhibit an electrical switching ratio of more than two orders of magnitude and obvious infrared modulation performance. It not only offers a viable solution for broadening the application scope of VO2 but also contributes to understanding the role of defects in VO2 thin films for further research.

Application of ion modification for alteration of anode materials based on ZnO/CoZn nanostructures

During the conducted studies, it was established that the use of ion modification by irradiation with O+ and Ar+ ions makes it possible to elevate the degradation resistance of anode materials due to the effect of vacancy defect creation, the density of which varies with the irradiation fluence. At the same time, the analysis of changes in the band gap and the optical density value, expressing changes in structural distortions, revealed that ion irradiation leads to a rise in the stability of the preservation of electronic properties during long-term resource tests, which are inextricably linked with the degradation of ZnO/CoZn nanostructures due to oxidation processes as a result of lithiation. During assessment of changes in the parameters of the band gap and optical density of the samples after resource tests, it was found that the observed growth in these indicators is due to oxidation processes and partial amorphization due to the formation of oxide inclusions in the structure of nanowires, the presence of which is due to the interaction of nanostructures with the electrolyte over a long period of time during charging/discharging, which results in near-surface layer degradation due to the introduction of oxygen, and in the case of a long service life, to the formation of oxide inclusions that elevate the density of defects and vacancies in the structure. According to tests of synthesized ZnO/CoZn nanostructures as anode materials, it was found that the use of O+ and Ar+ ions not only leads to a growth in the degradation resistance of capacitive characteristics during long-term tests, but also to the stability maintenance of indicators with a reversible decrease in the charging rate at charging rate variation.