Publications by authors named "Alexander Syuy"

Due to their high refractive index, record optical anisotropy and a set of excitonic transitions in visible range at a room temperature, transition metal dichalcogenides have gained much attention. Here, we adapted a femtosecond laser ablation for the synthesis of WSe nanoparticles (NPs) with diameters from 5 to 150 nm, which conserve the crystalline structure of the original bulk crystal. This method was chosen due to its inherently substrate-additive-free nature and a high output level.

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Transition metal dichalcogenides (TMDCs), particularly molybdenum disulfide (MoS), have gained significant attention in the field of optoelectronics and photonics due to their unique electronic and optical properties. The integration of TMDCs with plasmonic materials allows to tailor the optical response and offers significant advantages for photonic applications. This study presents a novel approach to synthesize MoS-Au nanocomposites utilizing femtosecond laser ablation in liquid to achieve tunable optical properties in the near-infrared (NIR) region.

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The plasmonic sensors based on silver nanoparticles are limited in application due to their relatively fast degradation in the ambient atmosphere. The technology of ion-beam modification for the creation of monocrystalline silver nanoparticles (NPs) with stable plasmonic properties will expand the application of silver nanostructures. In the present study, highly-stable monocrystalline NPs were formed on the basis of a thin silver film by low-energy ion irradiation.

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The emergence of van der Waals (vdW) materials resulted in the discovery of their high optical, mechanical, and electronic anisotropic properties, immediately enabling countless novel phenomena and applications. Such success inspired an intensive search for the highest possible anisotropic properties among vdW materials. Furthermore, the identification of the most promising among the huge family of vdW materials is a challenging quest requiring innovative approaches.

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The exceptional optical, electrical, and mechanical capabilities of layered transition metal carbides, nitrides, and carbonitrides, called MXenes, revolutionized materials science. Among them, TiC received the most attention owing to the developed synthesis and processing methods, high conductivity, and pronounced plasmonic response. The latter, however, remains controversial with the open question of whether the peak around 800 nm has plasmonic or interband transition origin.

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The combination of photothermal and magnetic functionalities in one biocompatible nanoformulation forms an attractive basis for developing multifunctional agents for biomedical theranostics. Here, we report the fabrication of silicon-iron (Si-Fe) composite nanoparticles (NPs) for theranostic applications by using a method of femtosecond laser ablation in acetone from a mixed target combining silicon and iron. The NPs were then transferred to water for subsequent biological use.

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One of the hallmarks of Alzheimer's disease (AD) pathogenesis is the production, aggregation, and deposition of amyloid-β (Aβ) peptide. Surface-enhanced Raman spectroscopy (SERS) is a promising analytical technique capable of providing valuable information on chemical composition and molecule conformations in biological samples. However, one of the main challenges for introducing the SERS technique into the practice is preparation of scalable and at the same time stable nanostructured sensors with uniform spatial distribution of nanoparticles.

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MXenes are of great practical interest. While the physical properties of such a well-known MAX phase as TiAlC and the TiC MXene that is based on it have been widely studied, it is extremely important to study the properties of new four-component MAX-phases and the MXenes based on them. To do this, first, it is necessary to characterize the obtained materials.

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The possibility of controlled scalable nanostructuring of surfaces by the formation of the plasmonic nanoparticles is very important for the development of sensors, solar cells, etc. In this work, the formation of the ensembles of silver nanoparticles on silicon and glass substrates by the magnetron deposition technique and the subsequent low-energy Ar ion irradiation was studied. The possibility of controlling the sizes, shapes and aerial density of the nanoparticles by the variation of the deposition and irradiation parameters was systematically investigated.

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Recent developments in the area of resonant dielectric nanostructures have created attractive opportunities for concentrating and manipulating light at the nanoscale and the establishment of the new exciting field of all-dielectric nanophotonics. Transition metal dichalcogenides (TMDCs) with nanopatterned surfaces are especially promising for these tasks. Still, the fabrication of these structures requires sophisticated lithographic processes, drastically complicating application prospects.

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Layers of germanium (Ge) nanowires (NWs) on titanium foils were grown by metal-assisted electrochemical reduction of germanium oxide in aqueous electrolytes based on germanium oxide without and with addition of sodium silicate. Structural properties and composition of Ge NWs were studied by means of the scanning and transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and Raman spectroscopy. When sodium silicate was added to the electrolyte, Ge NWs consisted of 1-2 at.

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Due to particular physico-chemical characteristics and prominent optical properties, nanostructured germanium (Ge) appears as a promising material for biomedical applications, but its use in biological systems has been limited so far due to the difficulty of preparation of Ge nanostructures in a pure, uncontaminated state. Here, we explored the fabrication of Ge nanoparticles (NPs) using methods of pulsed laser ablation in ambient gas (He or He-N mixtures) maintained at low residual pressures (1-5 Torr). We show that the ablated material can be deposited on a substrate (silicon wafer in our case) to form a nanostructured thin film, which can then be ground in ethanol by ultrasound to form a stable suspension of Ge NPs.

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In this study, the nonlinear dynamics of nanoparticle concentration in a colloidal suspension (nanofluid) were theoretically studied under the action of a light field with constant intensity by considering concentration convection. The heat and nanoparticle transfer processes that occur in this case are associated with the phenomenon of thermal diffusion, which is considered to be positive in our work. Two exact analytical solutions of a nonlinear Burgers-Huxley-type equation were derived and investigated, one of which was presented in the form of a solitary concentration wave.

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We report on the structure and properties of novel SrBiO/SrCO and SrBiO/SrCO heterostructures with SrCO content varying from 10 wt% to 90 wt%. Formation of the heterostructures is succeeded via sintering technique and according to XRD, SEM, and EDX studies has resulted in highly crystalline materials with well-defined carbonate-bismuthate interfaces. In the reaction of photodegradation of phenol in aqueous solution the heterostructures demonstrated photocatalytic activity exceeding that of TiO.

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