Anatoli Popov

• PhD Dr Phys
• Senior Researcher at Institute of Solid State Physics University of Latvia

β-Ga2O3 ceramic was synthesized using the solid-state method, a well-established technique for creating ceramicmaterials with controlled composition and structure. The process began by pressing gallium oxide(Ga2O3) powder into a unified form, ensuring even distribution and compactness of the material. This pressedform was then subjected to annealin...

with Er-addition are synthesized and their structural and gas-sensitive properties are investigated. The addition of Er leads to the formation of a second Er 3 Ga 5 O 12 phase in the ZnGa 2 O 4 matrix and a larger active surface which allows an 11.1-fold increase in the response of ZnGa 2 O 4 to 10 4 ppm of CH 4. At the maximum response temperature...

This research aimed to explore the structural, electronic, mechanical, and vibrational properties of double half Heusler compounds with the generic formula Ti2Pt2ZSb (Z = Al, Ga, and In), using density functional theory calculations. The generalized gradient approximation within the PBE functional was employed for structural relaxation and for calc...

The surface topology and fractal dimension of ultrathin silver and gold films have been investigated utilizing atomic force microscopy. These films were formed at the early stages of metal deposition through thermal evaporation and have pre-percolation thicknesses. They contain both metallic and insulating (void) phases, making them metal–dielectri...

Interest in composite refractory ZrO2 – Al2O3 ceramics is due to the great prospects for their use in extreme conditions (radiation exposure, thermal cycling, exposure to aggressive environments) due to the high resistance to external influences of these ceramics. Moreover, the features of high resistance to external influences for this type of cer...

The optical properties of Mn⁵⁺ ions, which are responsible for the intense green–turquoise–blue coloration of Mn⁵⁺-based pigments and the near-infrared emission of phosphors, are the focus of this article. Mn⁵⁺ ions enter crystalline matrices in four-fold coordinated positions and can maintain their 5+ valence state when crystalline hosts meet the...

This research investigates the structural, electronic, mechanical, and vibrational properties of double half-Heusler compounds with the generic formula Ti2Pt2ZSb (Z = Al, Ga, and In) using density functional theory calculations. The generalized gradient approximation within the Perdew-Burke-Ernzerhof functional was employed for structural optimizat...

The luminescence properties of BaMgF4 ceramics synthesized using electron beam-assisted synthesis were investigated under vacuum ultraviolet (VUV) synchrotron excitation at a cryogenic temperature of T = 9 K. Their excitation spectra, measured over the 4–10.8 eV range, and corresponding luminescence spectra revealed a complex multicomponent structu...

In this study, chemical deposition was used to synthesize structures of Ga2O3 -NW/SiO2/Si (NW—nanowire) at 348 K and SnO2-NW/SiO2/Si at 323 K in track templates SiO2/Si (either n- or p-type). The resulting crystalline nanowires were δ-Ga2O3 and orthorhombic SnO2. Computer modeling of the delta phase of gallium oxide yielded a lattice parameter of a...

This paper presents the results of numerical simulations examining the thermodynamic processes during hydraulic hydrogen compression, using COMSOL Multiphysics® 6.0. These simulations focus on the application of hydrogen compression systems, particularly in hydrogen refueling stations. The computational models employ the CFD and heat transfer modul...

This study offers a comprehensive review of gallium oxide (Ga₂O₃)-based photodetectors, emphasizing their applications in solar-blind UV detection and missile tracking systems. Using bibliometric, patent, and content analysis, research trends and technological developments were examined through an extensive review of scientific publications and pat...

This paper presents the results of numerical simulations examining the thermodynamic processes during hydraulic hydrogen compression, using COMSOL Multiphysics® 6.0. These simulations focus on the application of hydrogen compression systems, particularly in hydrogen refueling stations. The computational models employ the CFD and Heat Transfer modul...

Using synchrotron radiation, a comparative VUV excitation study of YAG ceramics doped with Eu3+ and Cr3+ ions under VUV excitation (10.5–3.7 eV) at 9 K was conducted in this work. Both ceramics exhibit distinct excitation peaks in the VUV region, indicating high-energy transitions related to the internal electronic levels of the dopants and interba...

This study presents an air quality monitoring system that employs the Arduino Uno microcontroller. The system is augmented with a moving average filter and data fusion techniques from BME680 and CCS811 sensors, which are designed to process and combine data from these sensors. The system was tested and analyzed empirically across a range of residen...

The paper demonstrates the possibility of forming specific nanostructures of the “parquet” type of nanowires on the InP surface. The resulting nanostructure is characterised by an ordered transverse and longitudinal relative shift of separate nanowires. A dislocation model is proposed that explains the mechanism of such structure formation. The num...

By means of the B3LYP and B3PW hybrid exchange-correlation functionals, as it is included in the CRYSTAL computer code, we performed ab initio computations for BaSnO3 and BaZrO3 perovskite (001) surfaces. For BaSnO3 and BaZrO3 perovskite (001) surfaces, with a few exceptions, all atoms of the upper surface layer relax inwards, all atoms of the seco...

The progress of modern electronics largely depends on the discovery and use of new materials with unique properties. One of such promising materials is carbon nanotubes. Their outstanding mechanical, thermal, and electrical properties open up new possibilities for creating small-sized electronic devices and improving the characteristics of existing...

This study comprehensively details the successful synthesis of a β-Ga2O3/por-GaAs/mono-GaAs heterostructure designed for portable solar cells. Employing a combination of electrochemical etching and high-temperature oxygen annealing, we engineered a heterostructure that exhibits both crystalline and amorphous phases. XRD, SEM, and Raman spectroscopy...

We report the results of synthesis of zinc selenide (ZnSe) nanocrystals into SiO2/Si track templates formed by irradiation with 200 MeV Xe ions up to a fluence of 107 ions/cm2. Zinc selenide nanocrystals were obtained by chemical deposition from the alkaline aqueous solution. Scanning electron microscopy, X-ray diffractometry, Raman and photolumine...

This study focuses on the wet chemical synthesis of AlxGa1−xAs nanostructures, highlighting how different deposition conditions affect the film morphology and material properties. Electrochemical etching was used to texture GaAs substrates, enhancing mechanical adhesion and chemical bonding. Various deposition regimes, including voltage switching,...

Herein, the impact of arsenolite oxide (As 2 O 3 ) crystallites on the structural and optical properties of porous gallium arsenide (GaAs) is examined, focusing on understanding the potential passivation effect and its influence on material stability and safety. Utilizing a comprehensive set of analytical methods, including cathodoluminescence (CL)...

This study presents theoretical and experimental investigations into the electron and hole color centers in BaFBr crystals, characterizing their electronic and optical properties. Stoichiometric BaFBr crystals grown by the Steber method were used in the experiments. Radiation defects in BaFBr crystals were created by irradiation with 147 MeV 84Kr i...

We propose a technique for the wafer-level testing of the gate dielectrics of metal–insulator–semiconductor (MIS) devices by the high-field injection of electrons into the dielectric using a mode of increasing injection current density up to a set level. This method provides the capability to control a change in the charge state of the gate dielect...

Modern solid-state physics increasingly focuses on the study of nanomaterials and the development of nanotechnologies. Various theoretical methods and research technologies are actively used to elucidate the significance of experimental results related to the study of solid-state defects. Progress in this field is likely associated with advancement...

By using DFT simulations employing the GGA/PBE and LDA/CA-PZ approximations, the effects of the Hubbard U correction on the crystal structure, electronic properties, and chemical bands of the cubic phase (Pm3m) of STO were investigated. Our findings showed that the cubic phase (Pm3m) STO's band gaps and lattice parameters/volume are in reasonably g...

The design of modern Cyber-Physical Systems (CPS) connects physical and digital realms from cloud systems to edge devices. Microservice architecture has been widely used for IT solutions and emerges as a promising approach for supporting CPS that are more efficient, adaptable, and interconnected. However, there is an increasing need to improve the...

The radiation-induced optical absorption at 1.5–5.5 eV (up to the beginning of fundamental absorption) has been analyzed in CVD diamond disks exposed to 231-MeV 132Xe ions with four fluences from 1012 to 3.8 × 1013 cm−2. The 5 mm diameter samples (thickness 0.4 mm) were prepared by Diamond Materials, Freiburg (Germany); the average grain size at gr...

The paper investigates the process of phase separation and morphology of organic-inorganic interpenetrating polymer networks (OI IPNs) based on the cross-linked polyurethane (PU), poly(hydroxyethyl methacrylate) (PHEMA) and poly(titanium oxide) (–TiO 2 –) n obtained by solgel method in the presence of poly(oxypropylene glycol) (POPG) at various mol...

Today, BaFBr crystals activated by europium ions are used as detectors that store absorbed energy in metastable centers. In these materials, the image created by X-ray irradiation remains stable in the dark for long periods at room temperature. As a result, memory image plates are created, and they are extended to other types of ionizing radiation...

We investigated the electronic structure of Mg-, Si-, and Zn-doped four-faceted [001]- and [110]-oriented SnO2 nanowires using first-principles calculations based on the linear combination of atomic orbitals (LCAO) method. This approach, employing atomic-centered Gaussian-type functions as a basis set, was combined with hybrid density functional th...

The radiation-induced optical absorption at 1.5-5.5 eV (up to the beginning of fundamental absorption) has been analyzed in CVD diamond disks exposed to 231-MeV 132Xe ions with four fluences from 1012 to 3.81013 cm-2. The 5-mm diameter samples (thickness 0.4 mm) were prepared by Diamond Materials, Freiburg (Germany), average grain size at growth si...

The paper presents the results of a comprehensive study of the structural, optical and strength features, changes in the morphology of grains of (1-x)WO3 – xZnO ceramics depending on the concentration of the initial components when they vary. Using the X-ray diffraction method, it was found that mechanochemical grinding of samples of (1-x)WO3 – xZn...

This study introduces an innovative method for synthesizing Cadmium Oxide /Cadmium Sulfide/Zinc Oxide heterostructures (CdO/CdS/ZnO), emphasizing their potential application in solar energy. Utilizing a combination of electrochemical deposition and oxygen annealing, the research provides a thorough analysis of the heterostructures through scanning...

Samples of ZrO2 ceramics with different concentrations of impurity titanium ions were synthesized by mixing zirconium and titanium oxide powders in different mass ratios. The X-ray diffraction analysis was used to determine the phase composition, lattice parameters, and crystallite size of the ceramics with varying dopant concentrations. Upon irrad...

Electrochemical deposition into a prepared SiO2/Si-p ion track template was used to make orthorhombic SnO2 vertical nanowires (NWs) for this study. As a result, a SnO2-NWs/SiO2/Si nanoheterostructure with an orthorhombic crystal structure of SnO2 nanowires was obtained. Photoluminescence excited by light with a wavelength of 240 nm has a low intens...

12th International Conference on Luminescent Detectors and Transformers of Ionizing Radiation (LUMDETR 2024) on June 16 – 21, 2024, in Riga, Latvia. https://www.cfi.lu.lv/lumdetr2024

Since the inception of the density functional theory (DFT) by Hohenberg and Kohn in 1964, it rapidly became an indispensable theoretical tool across various disciplines, such as chemistry, biology, and materials science, among others. This theory has ushered in a new era of computational research, paving the way for substantial advancements in fund...

The vibrational and electronic properties of several basic radiation defects in potassium bromide are computed at the quantum mechanical level using a periodic supercell approach based on hybrid functionals, an all-electron Gaussian-type basis set, and the Crystalcomputer code. The exciton energy in alkali halides is sufficient to create lattice de...

This study examines the dynamics and effectiveness of investments in Kazakhstan’s research and development (R&D). The primary aim is to assess the efficiency of scientific research activities in Kazakhstan by analyzing the relationship between R&D investments and scientific outputs across different periods. As a methodological approach, Data Envelo...

The annealing kinetics of the F and F+ color centers induced in MgAl2O4 single crystals under irradiation by 156-MeV 132Xe and 2.25-GeV 197Au ions are precisely measured via relevant optical absorption bands and analyzed in terms of the diffusion-controlled reactions between two pairs of anion Frenkel defects which determine thermal stability of ir...

The article is devoted to the study of the mechanism of nanopore formation in the junctions of polycrystal grains under the plastic deformation of a polycrystal due to the conservative sliding of lattice dislocations. A mechanism for the formation of a stress concentrator at the junction of the polycrystal grain boundaries is proposed. The possibil...

We, at the ab initio level, simulated the rearrangement magnitudes of the adjacent neighboring ions, surrounding the (100) surface F-center in ABO 3 perovskite matrixes. They are noticeably greater than the respective ionic shift magnitudes of the adjacent neighboring ions surrounding the bulk F-center. In ABO 3 perovskites, the electron charge is...

Thermoluminescent (TL) properties of monoclinic zirconium dioxide ceramics were studied in order to assess the possibility of their use for measuring high doses (on the order of kGy) of pulsed electron beams (130 keV). Two types of samples were used: those synthesized by sintering in an electric furnace at T = 700–1700 °C and those synthesized in a...

This study reveals a significant improvement in surface-enhanced Raman scattering (SERS) activity of Ag/ZrO2 substrates covered with a few-layer graphene preliminary exposed to ultraviolet (UV) light. The SERS-active substrates are formed by the “silver mirror” deposition of Ag nanoparticles on annealed zirconia blocks. The film composed of ~3 grap...

The aim of this study is to comprehensively examine the structural composition and properties of the AgAlS2 crystal during its high-pressure phase. This analysis delves into the second coordination environment of the crystal structure and elucidates the distinct transformations it undergoes during the phase transition. The band energy structure was...

The synthesis of β-Ga2O3 ceramic was achieved using high-energy electron beams for the first time. The irradiation of gallium oxide powder in a copper crucible using a 1.4 MeV electron beam resulted in a monolithic ceramic structure, eliminating powder particles and imperfections. The synthesized β-Ga2O3 ceramic exhibited a close-to-ideal compositi...

This article presents an enhanced method for synthesizing β-SiC on a silicon substrate, utilizing porous silicon as a buffer layer, followed by thermal carbide formation. This approach ensured strong adhesion of the SiC film to the substrate, facilitating the creation of a hybrid hetero-structure of SiC/por-Si/mono-Si. The surface morphology of the...

This article presents a study of the mechanism of porous space formation on the surface of single-crystal indium phosphide. The dissolution features of crystals of various types of conductivity and crystallographic orientation of the surface are demonstrated. The attention is focused on the formation of pore chain channels on the surface of n-InP (...

The objective of this research is to study the role of ion-induced secondary radiations on structural damage in LiF crystals irradiated with ∼ 10 MeV/u energy 12C, 50Ti, and 52Cr ions using experimental methods of nanoindentation, Atomic Force Microscopy, optical absorption, depth-resolved photoluminescence and chemical etching. In LiF crystals irr...

Samples of ZrO2 ceramics with different concentrations of impurity titanium ions were synthesized by mixing powders of zirconium and titanium oxides in various mass ratios. The phase composition and surface morphology of the studied ceramics were determined by X-ray phase analysis and scanning electron microscopy. It was found that irradiation of s...

In In this study, the optical properties of magnesium-aluminate spinel were examined after being irradiated with 220 MeV Xe ions. The research aimed to simulate the impact of nuclear fuel fission fragments on the material. The following measurements were taken during the experiments: transmission spectra in the IR region (190–7000) nm, optical abso...

The purpose of this study is to comprehensively analyze the influence of different fluences of irradiation with Xe23+ heavy ions on alterations in the structural, optical, and strength properties of AlN ceramics and to establish a connection between structural distortions and alterations in the optical and mechanical properties of the ceramics. X-r...

In recent years, much attention has been paid to research in the field of increasing resistance to external influences, including the corrosion resistance of steels and alloys exposed to aggressive environments or high temperatures. Interest in this area is due to the need to increase the service life of steel products, which will reduce the cost o...

This work presents a novel, cost-effective method for synthesizing Al x Ga 1−x As nanowhiskers on a GaAs surface by electrochemical deposition. The process begins with structuring the GaAs surface by electrochemical etching, forming a branched nanowhisker system. Despite the close resemblance of the crystal lattices of AlAs, GaAs, and Al x Ga 1−x A...

In this work, using photoluminescence (PL), optical absorption (OA), Raman spectroscopy (RS), and atomic force microscopy (AFM), the radiation damage of BaFBr crystals irradiated with 147 MeV 84Kr ions to fluences (1010–1014) cm2 was investigated. The manifestations of the oxygen impurity contained in the studied crystals on the effects associated...

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The aim of this paper is to test the previously stated hypothesis and several experimental facts about the effect of the ion flux or ion beam current under irradiation with heavy ions on the radiation damage formation in the ceramic near-surface layer and their concentration. The hypothesis is that, when considering the possibilities of using ion i...

CdxTeyOz nanocomposite films were grown by the SILAR method on the CdS/ZnO surface during cyclic processing in precursor solutions followed by removal of excess reagent from the surface of the substrate by washing in hydrogen peroxide. To stabilise the surface states and saturate with oxygen, the surface was annealed in a diffusion furnace. XRD, RA...