Physics and Chemistry of Solid State is an international peer-reviewed academic journal devoted to fundamental and applied research in condensed matter physics, solid-state chemistry, and materials science. The journal welcomes contributions in the following subject areas: physical and mathematical sciences, chemical sciences, engineering and technical sciences. The journal publishes reviews and original research papers. Journal's issues has been published from 2000. Media identifier (National): R30-02046 ISSN 1729-4428 (Print) E-ISSN 2309-8589 (Online) 2024 Scopus Metrics: CiteScore: 1.8 (2023 - 1.7; 2022 - 1.1; 2021 - 0.8) SJR: 0.255 SNIP: 0.57 (2023 - 0.431) Quartile: Q3 Frequency: quarterly
Vasyl Stefanyk Carpathian National University
Recent progress and challenges in CIGS and CZTS thin film photovoltaic technologies. Review
This review provides a comprehensive analysis of the current state, progress, and challenges of thin-film solar cells based on Cu(In,Ga)Se₂ (CIGS) and Cu₂ZnSn(S,Se)₄ (CZTS(Se)) absorber materials. The study highlights the global transition toward renewable energy, emphasizing the advantages of thin-film photovoltaic technologies as cost-effective, material-efficient, and flexible alternatives to conventional crystalline silicon solar cells. CIGS-based devices demonstrate high power conversion efficiencies exceeding 23%, wide tunability of the bandgap, and excellent long-term stability, making them among the most mature thin-film technologies. However, their dependence on scarce and costly elements such as indium and gallium motivates research into earth-abundant alternatives. CZTS(Se) materials, composed of non-toxic and widely available elements (Cu, Zn, Sn, S, Se), offer a sustainable substitute with comparable optical properties and tunable bandgaps (1.0–1.5 eV). Despite lower efficiencies (currently up to 15.8%), ongoing progress in controlling phase purity, defect passivation, and band alignment is rapidly improving device performance. Key research directions include the optimization of absorber synthesis, defect engineering, alkali-metal and cation doping, and development of environmentally benign, cadmium-free device architectures. The review outlines both the technological maturity of CIGS and the emerging potential of CZTS(Se), identifying critical challenges and future pathways toward high-efficiency, sustainable thin-film photovoltaics.
Copyright (c) 2026 R.S. Yavorskyi, M.V. Krykhovetskyi https://creativecommons.org/licenses/by/4.0/deed.uk
Application of Ar⁺ion implantation for obtaining nanocontacts on the GaP (111) single crystals surface
Ultrathin ohmic contacts were fabricated on GaP(111) single crystals using argon ion (Ar⁺) implantation at an energy of E₀ = 2 keV and a dose of D = 2 × 10¹⁷ cm⁻², under high vacuum conditions (10⁻⁷ Pa). Post-irradiation analysis revealed a significant enrichment of the surface with gallium, reaching a concentration of approximately 90 at.%. Subsequently, a nickel (Ni) film with a thickness of about 1000 Å was deposited onto the GaP(111) surface to form the contact. This metallization step led to a three- to fourfold reduction in the total thickness of the contact layer compared to conventional approaches. Upon thermal treatment at T = 850 K, the initially disordered GaP(111) layers recrystallized, resulting in a polycrystalline contact structure. After annealing, the thickness of the contact layer increased by approximately 1.5 times, reaching 400–450 Å, which is still around 2.5 times thinner than the characteristic thickness (dₙ) in the Ni/pure-GaP system. These findings demonstrate that ion implantation, followed by controlled metallization and annealing, provides an effective route for producing ultrathin, thermally stable ohmic contacts for GaP-based semiconductor devices.
Copyright (c) 2026 Baltokhodzha Ermatovich Umirzakov , Sardor Burkhonovich Donaev , Ganjimurod Mamir ugli Shirinov, Rashad Abaszade http://creativecommons.org/licenses/by/3.0/
Superconductivity of topological insulator Bi2Se3
The present paper deals with investigation of magnetoresistance and temperature dependencies of resistance for Pd-doped Bi2Se3 whiskers. The samples with palladium doping concentration of (1 ÷ 2) × 1019 cm−3 were studied in the temperature range of 1.5 ÷ 77 K and magnetic field induction up to 1.5 T. A sharp drop in the whisker resistance was found at the temperature of 5.3 K and 2.2 K. This effect can be explained as a contribution of superconductivity at temperatures under 5.3 K. Low temperatures magnetoresistance investigations allow to obtain critical magnetic field for the superconductivity of about 1.5 T.
Copyright (c) 2026 Mykhailo Mykytiuk, Anatoly Druzhinin, Ihor Ostrovskii, Natalia Liakh‑Kaguy http://creativecommons.org/licenses/by/3.0/
Structure, morphology and conductive properties of thermochemically activated carbon material from walnut shells
The method of thermochemical activation with orthophosphoric acid was used to obtain porous carbon material from walnut shells. The effect of the activation temperature on the structural, morphological and conductive properties of the carbon material was studied. The structural and morphological characteristics of the carbon samples were characterized using low-temperature adsorption porometry, SEM and Raman spectroscopy. It was shown that thermochemical activation with orthophosphoric acid allows obtaining porous carbon materials with a specific surface area of 734 - 1385 m2/g, depending on the activation temperature. The conductive properties of the obtained porous carbon materials were studied using the impedance spectroscopy method.
Copyright (c) 2026 Nataliia Ivanichok, Bohdan Rachiy, Volodymyr Mandzyuk, Oleh Ivanichok, Taras Lysiv http://creativecommons.org/licenses/by/3.0/
A Fractal Approach to Evaluating the Thermal Conductivity of ZrB2–C Composite Ceramic Materials
A pressing issue in materials science is the controlled application of ceramic composite materials at high temperatures in modern technologies, particularly in nuclear physics, atomic energy, aerospace, and rocket engineering. This study investigates the correlation between the thermal conductivity of synthesized ZrB2–C ceramic composites and their microstructural features using fractal analysis. The composites were produced via high-temperature reactive synthesis from boron and zirconium carbide powders. Scanning electron microscopy (SEM) and backscattered electron (BSE) modes was used to obtain micrographs of the fracture surfaces. These images were analyzed using the Box Counting method with ImageJ and FracLac software to determine two fractal parameters: fractal dimension and lacunarity. A strong inverse correlation was observed between lacunarity and thermal conductivity. The study demonstrates that fractal analysis, particularly the lacunarity parameter, can serve as a useful tool for assessing heat transfer potential in two-phase ceramic composites, especially when conventional measurement methods are impractical.
Copyright (c) 2026 A.S. Shirinyan, L.V. Marynchenko, O.I. Nizhelska http://creativecommons.org/licenses/by/3.0/
The photophysical properties of strongly coupled hybridized light-matter states in a classical physics perspective
The Lorentz oscillator model is applied to a strongly coupled hybridized light-matter state. It is noted that the real part of the index undergoes rapid change in the area of the so-called “dark states.” This property of hybridized light-matter states could allow them to function as unorthodox optical materials in which their absorptive and refractive properties are selectively manipulated. In this manuscript, basic properties of hybrid light-matter states, also referred to as cavity polaritons, are reviewed. The Lorentz oscillator model is then applied to two types of light-matter states, one formed from coupling between a single exciton and a single cavity photon, and one formed from coupling two excitons to a single cavity photon. Furthermore, the simple harmonic oscillator model is used to estimate the spring constant of a diatomic molecule under strong light-matter coupling conditions. It is found that the spring constant is directly related to the photonic character of the system, with a higher photonic character resulting in a smaller spring constant.
Copyright (c) 2026 Aleksandr Avramenko http://creativecommons.org/licenses/by/3.0/
The influence of growing in a hydrogen atmosphere on the micromechanical properties of Cd1-xZnxTe single crystals
У статті досліджено вплив водневої атмосфери під час росту кристалів Cd 1–x Zn x Te (CZT) на їхню мікротвердість та стійкість до руйнування. Ми виявили, що мікротвердість кристалів, вирощених у водні, вища порівняно зі зразками, отриманими в інертному середовищі, що, ймовірно, пов'язано з кращим упорядкуванням зв'язків та зменшенням щільності структурних дефектів. Спостерігалося збільшення стійкості до руйнування разом зі збільшенням мікротвердості, що свідчить про зменшення кількості дефектів у кристалічній решітці. Виявлені закономірності пояснюються пасивацією електрично активних дефектів воднем, що сприяє зменшенню кількості структурних порушень та відновленню ковалентних зв'язків у кристалічній решітці. Отримані результати є важливими для вдосконалення технологій вирощування напівпровідникових матеріалів детекторного призначення з контрольованими механічними властивостями.
Copyright (c) 2026 Yu. Pavlovskyy, V. Brytan, O. Kuzyk, Yu. Skvarok, Yu. Kovalchuk, A. Tymkiv http://creativecommons.org/licenses/by/3.0/
The Effect of TiH2 Particle Size on its Properties
Titanium-based composites have the potential to replace traditional materials in the automotive, aerospace and other industries. This is facilitated by their excellent mechanical, physical, thermal properties, and their strength-to-weight ratio. In the presented work, the influence of the particle size of hydrogenated titanium on its conductive properties was investigated. Hydrogen saturation was carried out using the Stevenson apparatus, the hydrogen content was 3.8%. After that, the initial sample was subjected to high-energy grinding. 3 main particle sizes were identified for further research: 100 μm, 100-200 μm, over 200 μm. Resistometric studies have shown that particles of 100-200 μm are characterized by an order of magnitude higher electrical conductivity than other particle sizes (8 (Ohm·cm)-1), which is due to the maximum contact between neighboring particles and their optimal geometry when packing the powder sample. Based on this powder size, a nanocomposite with carbon nanostructures was synthesized using mechanosynthesis, which is characterized by an order of magnitude higher electrical conductivity compared to the original components, which indicates the possibility of using such materials in the electrical engineering industry.
Copyright (c) 2026 V.V. Moklyak, H.Yu. Mykhailova, M.M. Humeniak, V.A. Dekhtyarenko, O.O. Stasiuk http://creativecommons.org/licenses/by/3.0/
Effect of plasmonic nanoparticles on the electrophysical characteristics of triboelectric layers
This paper examines the effect of spherical metal nanoparticles embedded in a triboelectric layer on its electrical properties. A hypothesis is proposed regarding the mechanism by which surface plasmon resonance excited in metal inclusion particles influences the charge density on the contacting surfaces of a triboelectric nanogenerator and its operational characteristics. The effective dielectric function of the spherical metal nanoparticles–polydimethylsiloxane composite is determined using the effective medium approximation. The frequency dependences of the effective dielectric function real and imaginary parts of the triboelectric layer are calculated in the frame of the classical and corrected Maxwell-Garnett models. It is established that the extrema of the dielectric function frequency dependence for the metal nanoparticle–polydimethylsiloxane composite correspond to surface plasmon resonance in the inclusion particles. The effect of the nanoparticle-inclusion size on the nature of the frequency dependences is revealed, namely, an increase in the amplitude of the maxima and their “blue” shift with decreasing particle radius. The polarization charge density on the surface of the triboelectric layer is calculated for spherical inclusion particles of different radii, made of different metals, and at different concentrations. A qualitative similarity is demonstrated between the frequency dependence curves of the effective dielectric function real part and the polarization charge surface density.
Copyright (c) 2026 A.V. Korotun, V.P. Kurbatsky, R.Yu. Korolkov, H.V. Moroz http://creativecommons.org/licenses/by/3.0/
Electrical properties of La modified SrBi4Ti3.975Zr0.025O15 ceramics
Polycrystalline Sr(Bi4-xLax)(Ti3.975Zr0.025)O15 (x = 0.025, 0.05 ,0.075 and 0.1) is prepared by solid-state method. It was characterized by X-Ray Diffraction (XRD), Scanning Electron Micrograph (SEM) and Energy Dispersive Spectra (EDS). From XRD and SEM analysis, phase formation is identified and particle size is calculated. Compositions are confirmed from EDS spectra. The dielectric, ferroelectric and piezoelectric studies are investigated. Remnant polarization (Pr) is found to increase, Curie temperature (Tc) and dielectric constants are found to be decreased, and electromechanical coupling coefficients and piezoelectric charge coefficients are found to be increased as the concentration of La increases
Copyright (c) 2026 B. Mamatha https://creativecommons.org/licenses/by/4.0/deed.uk
Selective laser melting of Al-Cu-Fe based alloys using elemental powder blends
In this work, the conditions for obtaining the Al63Cu25Fe12 alloy from a mixture of elemental powders by selective laser melting were investigated. In addition to directly synthesizing the alloy using the mentioned method, the aim of this work was also to identify the conditions for the formation of quasi-crystalline phases, which have special mechanical properties. Selective laser melting was performed at different powers and geometries of laser irradiation in air and in vacuum. Scanning electron microscopy and X-ray phase analysis methods were used to study the prepared alloys. It has been shown that, in addition to the generally accepted modes of laser alloy synthesis, focusing the laser beam on the surface of the samples plays an important role in this process.
Copyright (c) 2026 Ihor Shtablavyi, Yuri Kulyk, Andrii Pauk, Nazar Popilovskyi, Maryna Yatsevych, Stepan Mudry https://creativecommons.org/licenses/by/4.0/deed.uk
Dielectric properties and electrical conductivity of FeGa0.8In1.2Se4 crystals on alternating current
Dielectric permeability and electrical conductivity of FeGa0.8In1.2Se4 crystal at different frequencies and temperatures were studied. It was determined that the real and imaginary parts of the dielectric permittivity were subjected to a significant degree of dispersion, which has the character of relaxation. In this crystal, the regularity σ ~ fS (0.1≤ S ≤ 1.0) is satisfied for electrical conductivity in the temperature range 295 ÷ 358 K and the frequency range 2·104 ÷ 106 Hz and it is assumed that there is a hopping conduction mechanism. The activation energy of charge carriers for the FeGa0.8In1.2Se4 crystal was determined.
Copyright (c) 2026 Namiq Niftiyev, Faik Mammadov, Asmet Azizova, Khanlar Hashimov, Mahammad Babanly https://creativecommons.org/licenses/by/4.0/deed.uk
Qualitative analysis of differences in the physical properties of few-layer quasi-2D crystals
Quasi-2D crystals (graphite, layered crystals А3В6, transition metal, etc.) have a variety of unique properties that can vary widely by external factors, intercalation, etc. This explains the interest in such crystals both from the point of view of fundamental research and from that of practical use. The technological possibilities of obtaining few-layer fragments of quasi-2D crystals have become another way to achieve properties not inherent in bulk materials. This article presents a generalized model of few-layer fragments, which qualitatively highlights the factors responsible for the differences between bulk quasi-2D samples and their few-layer counterparts. The model’s conclusions are in qualitative agreement with experimental and theoretical findings reported by other authors. This study also addresses the impact of external factors on the physical properties of samples with varying layer thicknesses.
Copyright (c) 2026 Bohdan Lukiyanets, Dariya Matulka https://creativecommons.org/licenses/by/4.0/deed.uk
Optical and Structural Properties of CdTe Thin Films for Photovoltaic Applications
The paper presents the results of a study of cadmium telluride thin films grown on glass substrates by open evaporation in vacuum. Based on experimentally measured optical transmittance spectra of the films, their optical parameters were calculated using the OPTIFIT software environment. A comparative analysis of the film thickness measured with a profilometer and the OPTIFIT model showed only minor deviations in thickness for thin films up to 3-4 µm. Analysis of AFM images revealed a significant improvement in the structural characteristics of CdTe films, in particular a reduction in the number of defects and in surface roughness for thicknesses of 500–2500 nm, which contributes to increasing the efficiency of photovoltaic energy converters.
Copyright (c) 2026 B.S. Dzundza, V.Y. Fedenko, R.S. Yavorskyi, R.V. Ilnytskyi https://creativecommons.org/licenses/by/4.0/deed.uk
Influence of structure on the magnetoresistive properties of discontinuous multilayer structures based on Ni80Fe20 and SiO
This work presents the results of experimental studies on the structure and magnetoresistive properties of [Ni80Fe20(dNi80Fe20)/SiO(5)]5/S discontinuous multilayer structures. It is shown that for both as-deposited and annealed structures at temperatures of 400, 500, 600, and 700 K with an effective thickness of Ni80Fe20 layer dNi80Fe20 = 6-8 nm, anisotropic magnetoresistance is observed. It was found that annealing at 500 K for samples with dNi80Fe20 = 4-5 nm leads to the emergence of isotropic magnetoresistance due to insulating interlayers forming between magnetic granules. After annealing at 600 K, anisotropic magnetoresistance reappears in structures with dNi80Fe20 > 4 nm due to the breakdown of the structural continuity of the insulating layers.
Copyright (c) 2026 O.V. Pylypenko, I.M. Pazukha, S.R. Dolhov-Hordiichuk, A.M. Lohvynov, K.V. Tyschenko, B.S. Ruban, A.M. Chornous, V. Komanicky, Yu.O. Shkurdoda https://creativecommons.org/licenses/by/4.0/deed.uk
Experimental studies and physical and mathematical modeling of the influence of the inhomogeneity of the temperature field along a carbon particle on the characteristics of its ignition, burning and extinction
This work is devoted to experimental studies and physico-mathematical modeling of high-temperature heat and mass transfer and chemical transformation of carbon particles, accounting for internal thermal conductivity. The relevance of the study is driven by the need to improve the accuracy of predicting the ignition, combustion, and extinction characteristics of solid fuels in thermotechnical processes. Most theoretical approaches utilize an isothermal particle approximation, which can lead to errors in determining the induction period and burnout time, particularly for particles in the submillimeter and millimeter range. A non-isothermal model is proposed, incorporating internal thermal conductivity within the particle, oxidation reactions, and heat exchange via convection and radiation. Numerical calculations were performed for a diameter range of 100–1000 μm, with an analysis of temperature fields and gradients during the ignition and extinction stages. It is shown that as the particle diameter increases, the temperature differential between the surface and the center grows, while the radial temperature gradient decreases due to the spatial expansion of the temperature field and the increase in transient thermal time. Experimental studies with millimeter-sized particles revealed significant temperature gradients at the ignition stage and identified the moment of ignition by the maximum value of the time derivative of the particle's surface temperature. A comparison of calculations using isothermal and non-isothermal models demonstrated a systematic overestimation of ignition and burning time when internal thermal conductivity is neglected. It is shown that in the range of small particle sizes, failing to account for internal thermal conductivity leads to a predicted absence of ignition. The results obtained confirm the necessity of a non-isothermal description for the correct prediction of combustion characteristics for carbon particles larger than 200 μm.
Copyright (c) 2026 S.G. Orlovska https://creativecommons.org/licenses/by/4.0/deed.uk
Structure of titanium dioxide, doped with Zr and Nb
Analysis of the structure and phase change of nanodispersed titanium dioxide (obtained using sol-gel method) intercalated with zirconium and niobium (based on the following precursors: zirconium butoxide Zr(OC(CH3)3)4 and niobium ethoxide Nb(OCH2CH3)5) has been performed. X-ray analysis revealed anatase and brookite phases for ТіО2<Zr> and their transformation into rutile upon annealing at a temperature of 1120 K. It is shown that intercalation of niobium in ТіО2 stabilizes anatase phase (without transformation into rutile).
Copyright (c) 2026 I.M. Budzuliak, L.S. Yablon, I.I. Budzuliak, V.O. Kotsiubynskyi, R.V. Ilnytskyi, L.M. Humeniuk https://creativecommons.org/licenses/by/4.0/deed.uk
Z-scan, antibacterial activity and photocatalytic studies of sodium bromide-doped L-alanine single crystals
The slow evaporation method was used to produce sodium bromide-doped L-alanine (SBLA) single crystals at room temperature. Advanced techniques including dielectric, cyclic voltammetry (CV), Vickers microhardness, impedance, Energy-dispersive X-ray spectroscopy (EDAX), Scanning electron microscope (SEM), Photocatalytic activity test, ultrasonic study, Z-scan, laser damage threshold (LDT) and antibacterial activity studies were used to investigate the grown SBLA crystal. To determine the SBLA crystal's specific capacitance value, a CV research was conducted. The SBLA crystal's stiffness constant, yield strength, work hardening coefficient, and hardness were all assessed using Vickers microhardness testing.The structure of the produced single crystals, which resemble flowers, was examined using a scanning electron microscope (SEM). To determine the percentage amount of the elements in the SBLA sample, an EDX analysis was conducted. The dielectric loss and dielectric constant of the SBLA crystal have been ascertained using a dielectric investigation.The Nyquist diagram of the sodium bromide-doped L-alanine single crystal value of the bulk resistance and grain boundary resistance are found by impedance analysis. The density, velocity, compressibility and bulk modulus values of the aqueous solution of SBLA crystal were evaluated by ultrasonic interferometer analysis. The photocatalytic activity SBLA sample was tested to check the dye removal in congo red and methylene blue dyes. The SBLA crystal’s nonlinear refractive index (n2) and nonlinear absorption coefficient (b), and also third-order nonlinear optical susceptibility (χ(3)) values were determined by investigation of Z-scan. The antibacterial activity and LDT studies were also carried out for sodium bromide-doped L-alanine (SBLA) crystal and the results are analyzed.
Copyright (c) 2026 S. Usha, P. Selvarajan, S. Lincy Mary Ponmani, S. Gracelin Juliana https://creativecommons.org/licenses/by/4.0/deed.uk
Neodymium Doped Copper Ferrite Nanocomposites as an Effective Magnetic Catalyst for the Organic Dyes Decomposition
Neodymium-substituted copper ferrite nanoparticles with composition CuNdxFe2−xO4 (x = 0.00–0.11) were synthesized via the sol–gel autocombustion method and systematically analyzed for their structural, optical, and photocatalytic properties. X-ray diffraction combined with Rietveld refinement confirmed the formation of a dominant spinel ferrite phase with minor secondary phases, while Nd incorporation induced a reduction in crystallite size and an increase in lattice microstrain without disrupting the long-range spinel structure. Optical studies based on diffuse reflectance UV–Vis spectroscopy and Tauc analysis revealed direct allowed electronic transitions and a non-monotonic variation of the optical band gap (2.7–3.1 eV) as a function of Nd content, attributed to the combined effects of lattice distortion, defect states, and cation redistribution. Photocatalytic performance was evaluated through Congo Red degradation under light irradiation in the presence of H2O2. Nd substitution significantly enhanced photocatalytic activity, with CuNd0.09Fe1.91O4 showing the highest degradation efficiency (~96%), whereas the highest apparent rate constant (Langmuir–Hinshelwood model) was observed for CuNd0.05Fe1.95O4. The results demonstrate that controlled Nd substitution effectively tunes the structural and electronic properties of CuFe2O4, leading to improved photocatalytic performance and highlighting its potential for wastewater treatment applications.
Copyright (c) 2026 M. Mokliak, R. Ilnytskyi, L. Kaykan, Yu. Mazurenko, L. Turovska, M. Moiseienko, V. Moklyak, V. Sheketa https://creativecommons.org/licenses/by/4.0/deed.uk
Novel and Easy Spectroscopic Method for Cadmium Estimation in Aqueous Samples
A simple and an accurate method has been developed for the estimation of cadmium spectroscopically in water and soil systems. The method involves chelate bond formation of Dimethylglyoxime ligand with Cadmium under feasible and basic medium environment. The method shows 1:2 formation bond in between Cadmium and Dimethylglyoximine. The optimal condition for the formation of bonding between Cadmium and DMG and consequent determination of cadmium was established. The applicability of Beer-lambert law was found in between 0.03 to 0.900 μg/ml. The molar extinction coefficient of Cd (DMG) complex was found to be 1.5 × 105 mol-1 cm-1. Finally, the method was compared with the already available methods and comparative results shows that the study carried out in the said research seems better and economically feasible.
Copyright (c) 2026 Mohd Amin Mir, Syed M. Hasnain, K. Andrews http://creativecommons.org/licenses/by/3.0/
An Application of The Thermodynamic Approach to Explain the Shape Selection During Light-Induced Growth of Silver Nanoparticles
Synthesis of silver nanoparticles of different shapes and sizes by the chemical reduction of Ag+ may be strongly influenced by the light irradiation. A key question is understanding the mechanism underlying the transformation of initial spherical seeds into prisms and decahedra under visible light. In this study, we summarize existing theories of light-induced nanoparticle growth and apply a thermodynamic approach to shape selection during the synthesis of silver nanoparticles. We propose a universal thermodynamic model that explains both the influence of light on the synthesis and transformation of silver nanoparticles in the presence of H2O2. This model accounts for the shift of the chemical potential relative to interfacial energies and the monoatomic step energies on the {111} facets. Our results demonstrate that the morphology of silver nanoparticles is determined primarily by photon energy rather than by the chemical nature of the reagents.
Copyright (c) 2026 Alina Korop, Tetyana Vakulenko, Yuriy Khalavka http://creativecommons.org/licenses/by/3.0/
Enhancing Properties of Metakaolin-Based Geopolymers: The Effect of Zirconia and Silica Nanosphere Additions
Geopolymers are known for its high compressive but low tensile strength due to its brittle nature, which restricts the use of geopolymers as structural material. It is important to enhance their mechanical performance by incorporating reinforcing materials. This research examines the contribution of silica nanospheres and zirconia to enhance the tensile strength of geopolymer composites utilizing metakaolin. Geopolymers were prepared from an 8M NaOH and sodium silicate activator, which was prepared for 24 hours prior to mixing in a ratio of 2:1. Confirmation of the amorphous silica presence, monoclinic and tetragonal zirconia, and crystalline phases in metakaolin including quartz, mullite, and hematite was verified using X-ray diffraction (XRD) analysis. The scanning electron microscope (SEM) showed that both silica nanospheres and zirconia resulted in a more densely packed microcomposite material with less porosity. Diametral tensile strength (DTS) at 28 days was seen to improve from 2.24 MPa (control) to 2.58 MPa with 80% silica and 3.61 MPa with 60% zirconia and 20% silica nanospheres. These improvements showed that nanomaterials such as silica can enhance the densification of the matrix while zirconia contributes structural reinforcement for improved mechanical properties. The findings here are consistent with earlier work that demonstrated the synergistic effects of silica nanospheres and zirconia to improve geopolymers performance. Findings from this study further demonstrates modified geopolymers can be used in applications requiring high mechanical strength but would require additional investigation to determine its durability and thermal properties to use them in structural and functional applications.
Copyright (c) 2026 Mevy Firdaus, Andrie Harmaji, Eva Febrina, Imelda Ruth, Bambang Sunendar, Ibnu Suryatmojo http://creativecommons.org/licenses/by/3.0/
Magnetic composites Fe3O4 bаsed for the purification of polluted water
Fe₃O₄ magnetic nanocomposite were synthesized from different techniques: Fe₃O₄ nanoparticles were synthesized by co- precipitation of salts in a carbon matrix (biochar, activated carbon) with the formation of Fe₃O₄/BC and Fe₃O₄/AC nanocomposites; and co-precipitation of FeCl₂/FeCl₃ with oleic acid, with formation of OL/Fe3О4 nanocomposite. Characterization techniques including XRD confirmed the spinel structure of composite matrix, with crystallite size around 20 nm. X-ray fluorescence analysis shows the presence of iron and oxygen elements, as well as impurity elements present in oleic acid and biomass carbon, respectively. The adsorption properties of all samples investigated for methylene blue (MB) dye removal. Adsorption tests were conducted at room temperature with magnetic separation of the spent adsorbent and photometric control at 665 nm. It found that magnetic composites effectively remove the dye, with AC/Fe₃O₄ achieving up to 96.6% removal at a concentration of MB 10⁻⁵ g/L.
Copyright (c) 2026 Andrew Kotsyubynsky, Diana Lynnyk, Halyna Hrytsuliak, Mariia Liaskovska, Yulia Kotsyubynska, Vitalii Hrytsuliak, Oleksandr Stanetskyi http://creativecommons.org/licenses/by/3.0/
Effect of Thiourea Concentration on Chemical Composition, Morphology and Nanocomposite Particle Distribution ZnO/ZnS Obtained by Electrochemical Anodizing Method
The presented study systematically investigated the influence of different thiourea (TU) concentrations on the synthesis and properties of ZnO/ZnS nanocomposites using an electrochemical anodization method. TU acted as a source of sulfur, allowing ZnS to form within the ZnO matrix. Structural, morphological, and compositional analyses were carried out using modern techniques: XRD, a Tescan Vega3 LMU microscope, ImageJ software with ParticleSizer, MorphoLibJ plug-ins, and energy dispersive X-ray spectroscopy (EDX). Chemical composition analysis confirmed that the increase in the concentration of TU leads to an increase in the content of ZnS. Elevating the concentration of TU in the electrolyte alters the makeup of the composite powders, shifting the balance from a predominance of lighter particles to a greater proportion of background particles within the mixture. This adjustment also leads to a significant reduction in the dimensions of the lighter particles, decreasing their length by half and their width by 1.5 times. Furthermore, this change in particle composition and size can have implications for the overall properties and performance of the composite materials. The parameters µ and σ decreases with the increase of the concentration of TU, and it testifies that particles are, on average, getting smaller and more uniform in size. The mode and median values follow this trend, decreasing consistently across the series, confirming the presence of finer and more monodisperse particles in samples 6–8. Understanding these relationships is crucial for optimizing material formulations to meet specific requirements in fields such as electronics, energy storage, and advanced manufacturing.
Copyright (c) 2026 O.M. Yanchuk, O.V. Smitiukh, O.V. Marchuk, S.V. Suprunovich, V.M. Kordan https://creativecommons.org/licenses/by/4.0/deed.uk
Computer modeling of diffusion processes in porous materials
Track structures belong to nanomaterials. Therefore, when studying such structures, it is important to take into account the general properties of nanomaterials. It is important to predict the structural features of the tracks, the configuration of defects on the inner surfaces of the tracks depending on the characteristics of the fast ions that create them. Using a computer experiment, it is possible to achieve results that are much more difficult to obtain in a conventional laboratory experiment. The formation of a nanotrack with the necessary structural parameters depends not only on ion-stimulated processes, but also on other methods of film processing, in particular chemical etching. Computer modeling of the passage of ion flows through nanotracks allows obtaining results that must be taken into account to improve the quality of modern biosensors. New algorithms and computer programs have been developed to solve these problems.
Copyright (c) 2026 Dietmar Fink , Arnold Kiv, Taras Kavetskyy, Dmytro Dyachok , Yurii Bondaruk , Alina Vinkovskaya , Nataliia Hoivanovych , Liudmyla Pankiv , Oksana Zubrytska , Oles Matskiv , Uliana Khromiak , Yaroslava Pavlyshak , Yuriy Pavlovskyy , Viktor Senkiv , Svitlana Monastyrska http://creativecommons.org/licenses/by/3.0/
AI-Based Model for Home Waste Separation Using Raspberry Pi 5 AI Kit
Effective domestic waste separation is also very critical to enhancing recycling and minimizing environmental pollution. Manual sorting, however, is labor-intensive, prone to errors and not practical to be widely adopted. In this paper, a new AI-controlled system of waste separation at home is presented, the computational power of the Raspberry Pi 5 AI Kit is used. It is a system consisting of a large-resolution camera, a conveyor belt system, and an edge deployment-optimized YOLOv5s convolutional neural network (CNN). The model is trained on the WasteNet dataset, with 25, 000 annotated images of five waste types (plastic, paper, glass, metal, and organic) and the classification accuracy of the model is 95.2%, with an average precision of 95.0%, and the time required to make an inference is 45 ms per frame. On average, the system consumes 5.2 W of energy and is therefore a cost-effective and energy-efficient system that can be used to manage household waste. It is possible to compare it with previous work and reveal that this technology is more effective regarding accuracy and latency and can be used as the effective tool to prompt environmentally friendly waste separation.
Copyright (c) 2026 H. A. Mutar, I. R. N. ALRubeei, I. V. Svyd, Haider TH. Salim ALRikabi, Abdul Hadi M. Alaidi http://creativecommons.org/licenses/by/3.0/
Synthesis and characterizations of ZnO nanoflowers prepared by one step microwave assisted solvothermal route for optoelectronic applications
In this study, blossom-shaped ZnO nanoflowers (NFs) were successfully synthesized using a rapid, one-step microwave-assisted solvothermal method with zinc nitrate hexahydrate and hexamethylenetetramine as precursors. The synthesis was completed within five minutes, relying solely on inexpensive reagents and eliminating the need for costly additives or high-temperature furnaces, thereby providing an efficient and economical route. Structural analysis through X-ray diffraction confirmed the high crystallinity of the ZnO NFs, while field emission scanning electron microscopy revealed their characteristic blossom-like morphology with an average particle size of approximately 18 nm. Optical properties were investigated by UV–visible spectroscopy, where a sharp absorption peak near 348 nm indicated good monodispersity. The optical band gap was determined as 3.22 eV using Tauc’s relation, which is significantly lower than that of bulk ZnO (3.51 eV), demonstrating a red shift. Moreover, the computed Urbach energy of 0.34 eV reflects low structural disorder in the nanostructures. The combination of rapid synthesis, controlled morphology, high crystallinity, and favorable optical characteristics underscores the novelty and strong potential of these ZnO nanoflowers for future optoelectronic and photonic device applications.
Copyright (c) 2026 Ravi S. Rai, Ruby Pant, Shristi Chaudhary, Rupesh Gupta, Chandrmani Yadav http://creativecommons.org/licenses/by/3.0/
Elastic Property Anisotropy in Inconel 718 Alloy Specimens Fabricated by Wire Arc Additive Manufacturing
This study investigates the anisotropy of elastic properties in Inconel 718 alloy specimens fabricated via Wire Arc Additive Manufacturing (WAAM). The crystallographic texture of the specimens was characterized using inverse pole figures (IPF) obtained in three mutually orthogonal directions: the build direction (along the layer deposition), the transverse direction (the scanning direction), and the normal direction (perpendicular to both build and transverse directions). The analysis revealed that the texture is well-described by a combination of ideal orientations with some degree of dispersion. Based on the elastic constants of Inconel 718 single crystals and the pole density data derived from the IPF, the Young's modulus, shear modulus, and Poisson's ratio were calculated for each of the three orthogonal directions. The results demonstrate that the Young's modulus in the normal direction is, on average, 10-11% lower than in the build and transverse directions. Conversely, the shear modulus and Poisson's ratio exhibit higher values in the normal direction. The study concludes that crystallographic texture is the dominant factor contributing to the observed anisotropy in the mechanical properties of the WAAM-fabricated Inconel 718 specimens. Therefore, strategic control of crystallographic texture during WAAM processing offers a pathway to engineer components with a tailored, optimized combination of mechanical properties.
Copyright (c) 2026 V.V. Usov, N.M. Shkatulyak, S.I. Iovchev, D.V. Pavlenko, D.E. Molochkov, R.A. Kulikovsky https://creativecommons.org/licenses/by/4.0/deed.uk