A5049923199- Phase-change materials and chalcogenides
- Glass properties and applications
- Muon and positron interactions and applications
- Material Dynamics and Properties
- Chalcogenide Semiconductor Thin Films
- Electrical and Thermal Properties of Materials
- Ferroelectric and Piezoelectric Materials
- Solid-state spectroscopy and crystallography
- Mineralogy and Gemology Studies
- Crystal Structures and Properties
- Nonlinear Optical Materials Studies
- Microwave Dielectric Ceramics Synthesis
- Graphene research and applications
- Optical and Acousto-Optic Technologies
- Luminescence Properties of Advanced Materials
- Advanced ceramic materials synthesis
- Copper Interconnects and Reliability
- Synthesis and characterization of novel inorganic/organometallic compounds
- Advancements in Battery Materials
- Gas Sensing Nanomaterials and Sensors
- Laser-Matter Interactions and Applications
- Quantum Dots Synthesis And Properties
- Liquid Crystal Research Advancements
- Dielectric properties of ceramics
- Chemical Synthesis and Characterization
Vlokh Institute of Physical Optics
2016-2025
Lviv University
2011-2025
Jan Długosz University
2015-2024
Electron (Ukraine)
2010-2024
Lviv State University of Life Safety
2013-2018
Institute of Physics
2000-2018
University of Pardubice
2018
Austin Peay State University
2018
Université de Rennes
2018
Centre National de la Recherche Scientifique
2018
To establish the validity of various proposed structural models, we have investigated structure binary ${\mathrm{As}}_{x}{\mathrm{Se}}_{100\ensuremath{-}x}$ chalcogenide glass family $(x\ensuremath{\leqslant}40)$ by high-resolution x-ray photoelectron spectroscopy. From composition dependence valence band, contributions to density states from $4p$ lone pair electrons Se and bonding $4s$ As are identified in top part band. The analysis $3d$ core-level spectra supports so-called chain crossing...
The long-term kinetics of physical ageing at ambient temperature is studied in Se-rich As–Se glasses using the conventional differential scanning calorimetry technique. It analysed through changes structural relaxation parameters occurring during glass-to-supercooled liquid transition heating mode. Along with time dependences glass (Tg) and partial area (A) under endothermic peak, enthalpy losses (ΔH) calculated fictive (TF) are as key parameters, characterizing ageing. latter shown to have...
Methodological possibilities of positron annihilation lifetime (PAL) spectroscopy applied to characterize different types nanomaterials treated within three-term fitting procedure are critically reconsidered. In contrast conventional analysis based on admixed positron- and positronium-trapping modes, the process nanostructurization is considered as substitutional positron-positronium trapping same host matrix. Developed formalism allows estimate interfacial void volumes responsible for...
The ZnS nanocrystals were prepared in chitosan solution (0.1 wt.%) using a wet ultra-fine milling. obtained suspension was stable and reached high value of zeta potential (+57 mV). changes FTIR spectrum confirmed the successful surface coating nanoparticles by chitosan. possessed interesting optical properties verified vitro. Four cancer cells selected (CaCo-2, HCT116, HeLa, MCF-7), after their treatment with nanosuspension, distribution studied fluorescence microscope. particles clearly...
Polyamorphic transitions driven by high-energy mechanical milling (nanomilling) are studied in thioarsenide As4Sen-type glassy alloys obtained melt quenching deviated from arsenic triselenide As2Se3 stoichiometry towards tetraarsenic pentaselenide (g-As4Se5) and tetraselenide (g-As4Se4). This employs a multiexperimental approach based on powder X-ray diffraction (XRD) analysis complemented thermophysical heat transfer, micro-Raman scattering (micro-RS) spectroscopy, revised positron...
Physical aging effects caused by prolonged natural storage $(\ensuremath{\sim}22\text{ }\text{years})$ in binary ${\text{As}}_{x}{\text{Se}}_{100\ensuremath{-}x}$ glasses are probed temperature-modulated differential scanning calorimetry. It is shown that all aged samples with $x<40$ reveal nonzero out-of-phase component of complex heat flow testifying physical effect. The first composition, which can be attributed to a so-called self-organized phase characterized the absence effect,...
The structure of homogeneous bulk As x S100− (25 ≤ 42) glasses, prepared by the conventional rocking–melting–quenching method, was investigated using high-resolution X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. It is shown that main building blocks their glass networks are regular AsS3/2 pyramids sulfur chains. In S-rich domain, existence quasi-tetrahedral (QT) S = As(S1/2)3 units deduced from XPS data, but with a concentration not exceeding ∼3–5% total atomic sites....
'Cold' crystallization in 80GeSe2-20Ga2Se3 chalcogenide glass nanostructurized due to thermal annealing at 380°C for 10, 25, 50, 80, and 100 h are probed with X-ray diffraction, atomic force, scanning electron microscopy, as well positron annihilation spectroscopy performed lifetime Doppler broadening of line modes. It is shown that changes defect-related component the fit experimental spectra nanocrystallized glasses testify favor structural fragmentation larger free-volume entities into...
Free volume and pore size distribution in functional micro macro-micro-modified Cu0.4Co0.4Ni0.4Mn1.8O4 ceramics are characterized by positron annihilation lifetime spectroscopy comparison with Hg-porosimetry scanning electron microscopy technique. Positron results interpreted terms of model implication trapping ortho-positronium decaying. It is shown that free traps the same type for macro modified ceramics. Classic Tao-Eldrup spherical approximation used to calculation nanopores smaller...
Abstract Thermal, optical, X-ray excited and magnetic methods were used to develop a microstructural model of physical ageing in Se-rich glasses. The glass composition As10Se90, possessing typical cross-linked chain structure, was chosen as object for the investigations. effect this revealed by differential scanning calorimetry, whereas corresponding changes its atomic arrangement studied extended absorption fine Raman solid-state 77Se nuclear resonance spectroscopy. Straightening–shrinkage...
The water-vapor sorption processes in nanoporous MgO-Al2O3 ceramics are studied with positron annihilation lifetime (PAL) spectroscopy employing trapping and positronium (Ps)-decaying modes. It is demonstrated that the longest-lived components four-term reconstructed PAL spectra characteristic lifetimes near 2 60-70 ns can be, respectively, attributed to ortho-positronium (o-Ps) traps nanopores 0.3- 1.5-1.8-nm radii. first o-Ps decaying process includes "pick-off" "bubbles" of liquid water,...
Mathematical models of degradation-relaxation kinetics are considered for jammed thick-film systems composed screen-printed spinel Cu0.1Ni0.1Co1.6Mn1.2O4 and conductive Ag or Ag-Pd alloys. Structurally intrinsic nanoinhomogeneous ceramics due to diffusing agents embedded in a phase environment shown define governing thermally induced degradation under 170 °C obeying an obvious non-exponential behavior negative relative resistance drift. The characteristic stretched-to-compressed exponential...
Abstract Mn 2+ and the trivalent europium (Eu 3+ )-doped MgGa 2 O 4 ceramics are characterized using a multi-experimental approach. The formation of spinel-structured is ascertained from X-ray diffraction (XRD) analysis. Morphology investigations with transmission electron microscopy (TEM) show irregularly shaped grains grain boundaries homogeneous distribution Eu ions. inability activator to penetrate bulk ceramic inferred positron annihilation lifetime spectroscopy data. doping shown...
The structure of binary GexSe100−x chalcogenide glass family (0≤x≤30) is determined by high-resolution x-ray photoelectron spectroscopy (XPS). On the basis compositional dependences fitting parameters for Ge and Se core level XPS spectra, ratio between edge- corner-shared tetrahedra determined. We find that this glasses with 20≤x≤30 almost constant a value same as high-temperature crystalline form GeSe2.
Technologically modified spinel ceramics are prepared from Al2O3 and 4MgCO3×Mg(OH)2×5H2O powders at 1200, 1300 1400 oC. The influence of sintering temperature on porous structure exploitation properties obtained humidity-sensitive MgO-Al2O3 studied. It is shown that increasing preparing 1200 to oC result in transformation pore size distribution tri- bi-modal including the open macro- mesopores with sizes tem hundreds nm nanopores until a few nm. studied ceramic elements electrical...