This work is devoted to a comprehensive study of the formation process and optical characteristics of multicomponent amorphous cobalt-based films. Thin-film samples were obtained by magnetron sputtering onto glass substrates. An amorphous Co70Fe5Mn3.5Mo1.5Si11B11 alloy was used as a target. To analyze the effect of the size factor, films were synthesized with deposition times of 10, 30, and 60 minutes. The disordered structure of the obtained films was investigated with Grazing Incidence X-ray Diffraction. The surface morphology was studied in detail by atomic force microscopy. AFM analysis revealed nanorelief with low structural regularity and a surface roughness of ~6 nm, allowing us to classify the surface as optically smooth in the visible wavelength range. The transmittance of the films was investigated over the spectral range 300-1100 nm. The obtained spectra show intense absorption in the blue region of the visible spectrum. A bathochromic shift of the main absorption maximum with increasing film thickness was recorded. An absorption maximum splitting was revealed for samples with a deposition time > 30min. The maximum absorption increases linearly with deposition time and, accordingly, with film thickness. The linear dependence of the peak intensity on deposition time is well consistent with the Bouguer–Lambert–Beer law.

The structure, mechanical and electrical properties of Zr-based melt-spun Zr–(Al)–Ni–Cr–Ag alloys were investigated as a function of elemental composition. X-ray diffraction reveals the structural evolution from fully amorphous to nanocrystalline states, with the latter containing Zr2Ni “big-cube” (space group Fd3̄m, cF96), fcc-Zr2Ni, and β-Zr phases depending on the alloying ratio: Cr-rich compositions (≥15 at.%) stabilize β-Zr within the amorphous matrix, whereas Ag-enriched alloys promote “big-cube” phase formation. Ag atoms can replace both Zr and Ni sites in the “big-cube” lattice, yielding a (Zr,Ag)2(Ni,Ag) solid solution and highlighting its role as a structural bridge between the amorphous and crystalline states. Nanoindentation measurements show that hardness increases from 6.5 GPa in fully amorphous ribbons to 10.12 GPa in three-phase nanocrystalline composites, with an H/E ratio of ~0.08 indicating predominantly covalent bonding, and the fracture strength of the amorphous alloys is ~2 GPa, exceeding literature values for related Zr-based systems. Electrical resistivity measurements over the 4–298 K range show that most alloys deviate from Matthiessen’s rule, exhibiting a negative temperature coefficient of resistivity consistent with the Mooij correlation; the presence of the icosahedrally ordered “big-cube” phase further increases resistivity relative to fully amorphous alloys.

In this work, the liquid-phase sintering of Zr45Cu45Al10 alloy nanoparticles was studied by molecular dynamics simulations. For the simulation, nanoparticles were obtained using previously simulated melt at a temperature of 1600 K. The simulations were carried out in the temperature range 1600–400 K when the nanoparticles were cooled. The cooling rate during the simulation was sufficient to ensure the formation of an amorphous phase. To analyze the structure of the sintered nanoparticles, we used total and partial functions of atomic distribution as well as distributions of coordination numbers. The temperature dependence of the interatomic distances was interpreted using of the hard and soft spheres model. A more detailed study of the particles structure obtained by the liquid-phase sintering method was performed using polyhedral analysis with different types of quasicrystalline order.

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.

In this work, we propose an optimized method for studying the free volume of disordered systems. The method was tested for the FCC structure of silver, and the results are consistent with those obtained by theoretical calculations. The proposed method was also used to calculate the free volume of bulk and nanoscale silver in liquid state. For this purpose, its structure was simulated using molecular dynamics method. The results of the study of the free volume of liquid and crystalline silver were compared. The transformation of the free volume of silver after melting was analyzed in detail. Additionally, correlations between void arrangements in the melt were identified. This method is applicable to a wide range of structures and multicomponent systems, and is particularly useful for the free volume of disordered

In this work, the formation of arrays of tin nanorods by rapid solidification of Sn-Zn alloys followed by selective chemical or electrochemical etching was investigated. Alloys with compositions close to the eutectic point were quenched from the melt using planar flow casting under different cooling conditions. X-ray diffraction and field emission scanning electron microscopy revealed that hypoeutectic alloys form porous structures as a result of zinc dissolution, while eutectic and hypereutectic compositions yield ordered tin nanorods aligned along the heat flux direction. The dimensions of the rods were found to depend on the cooling rate and substrate temperature, with finer and more ordered arrays obtained under rapid crystallization and higher thermal gradients. These results demonstrate that controlled rapid solidification followed by selective etching enables the scalable synthesis of ordered metallic nanorod arrays with tunable morphology.

In this work, the effect of laser treatment on the surface morphology and atomic structure of Fe73.5Nb3Cu1Si15.5B7 amorphous alloy in the form of ribbons and powders was studied. The results of the research made it possible to establish the optimal modes of laser processing of amorphous alloys that can be used for 3D printing of bulk amorphous materials. Laser processing was performed using a low-power laser with a maximum optical power of 50 W. The investigation was carried out by means of scanning electron microscopy and X-ray diffraction method. It is shown that irradiation of amorphous ribbons with a 15 W laser leads only to ablation of the alloy, and its melting begins at a power of 25 W. Based on the results of laser processing of amorphous ribbons, the optimal conditions for melting of amorphous powders obtained from the same alloy were selected. As a result of fusing amorphous powders, amorphous-nanocrystalline composites with a nanocrystal size of about 10 nm were obtained. The results of the study will help to improve the process of 3D printing of amorphous metal alloys for practical use.

Phase relations in the ternary system Cu-Ir-B have been experimentally established for the isothermal section at 600 degrees C via electron microprobe and X-ray powder diffraction analyses. Reinvestigation of the binary systems pertinent to the concentration areas of the current study confirmed the existence and crystal structure of compounds alpha-Ir2B3-x and Ir3B4 and indicated slightly higher solubility of Ir in Cu as compared to literature data. The formation of beta-Ir2B3-x was observed from ternary alloys annealed at 800 degrees C. Phase equilibria at 600 degrees C involve two previously reported ternary compounds, CuIr2B2-x (x = 0.52; space group Cmcm) and CuIrB (space group Fdd 2). In addition, a new ternary compound Cu 5+x Ir 5-x B 2 (x = 1.05; space group F 43 m ) was identified in as cast alloys. CuIr2B2-x and CuIrB crystallize with their own structure types while the new compound Cu 5+x Ir 5-x B 2 adopts the Pd5Cu5B2 structure type. The copper iridium borides obtained reveal different motifs of condensation of boron structural units. In the CuIr2B2-x structure, the Ir6 trigonal prisms (partly filled with B) inter-connect in two directions to form 2D layers; the blocks of three layers of prisms interchange along the longer axis of the unit cell with two stacked 44 Cu nets. Closely related arrangements are found in other intermetallic phases such as MAB phases. The building unit of CuIrB is a [BIr4] tetrahedron; the tetrahedra interconnect creating channels with interlinked and slightly waved chains of Cu. In the structure of Cu 5+x Ir 5-x B 2 , the groups of four [BM6] trigonal prisms (condensed through common edges) join via common vertices to form a framework enveloping extensive Cu structural units reminiscent to those, found in the fcc copper lattice (Cu6 octahedron augmented into tetrahedron by adding copper Cu4 tetrahedra). Two ternary compounds, CuIr2B2-x and CuIrB were targeted for analysis of their electronic and band structure, chemical bonding and physical properties (electrical resistivity as a function of temperature). The chemical bonding analysis revealed partially covalent Ir-B bonding in the metal boride subunits in both compounds. According to Bader charges analysis, copper atoms donate their electrons to more electronegative iridium atoms. CuIrB and CuIr2B2-x are expected to be metallic from the DFT calculations with number of bands crossing the Fermi level in both SO and non-SO case in good agreement with resistivity measurements. CuIrB is characterized by a small eDOS of 0.45 states/eV*f.u. on the Fermi level in comparison to a value of 2.75 states/eV*f.u. for CuIr2B2-x. Both compounds are characterized by a low residual resistivity and a low Debye temperature.

The magnetron sputtering method was used to synthesize amorphous cobalt-based thin films on a glass substrate. For this purpose, the amorphous alloy Co70Fe3Mn3.5Mo1.5Si11B11 was used as a target for magnetron sputtering. Thin-film metallic glass (TFMG) was deposited under carefully regulated conditions, enabling adjustment of film thickness. Structure analysis of the films was performed using Grazing Incidence X-ray Diffraction, revealing a disordered amorphous structure. Surface morphology was examined using FE-SEM and AFM, confirming high uniformity and smoothness. Film thickness was measured by optical interferometry, reaching up to about 135 nm after 60 minutes of sputtering. The results demonstrate that magnetron sputtering with an amorphous alloy as a target is an effective method for producing uniform, amorphous Co-based thin films and coatings with potential applications in magnetic and electronic devices.

The investigation addresses the structure of a Co-based alloy and its magnetic properties. The major applications of these materials are in the development of different sensors, which require materials with high permeability. The structure evolution processes need to be explored to clarify the main parameters determining the time-temperature stability. In the present paper, a nanocrystallization behavior of Co 67 Fe 4 Cr 7 Si 8 B 14 amorphous alloy manufactured in the form of a ribbon was studied using X-ray diffraction and sample vibromagnetometry methods. The structure evolution induced by the 30min isothermal annealing at a temperature range of 450 - 700 °C was studied by the X-ray diffraction method, and crystallization with hcp-Co, fcc-Co, and Co 2 B nanophases was revealed depending on the annealing temperature. According to thermomagnetic measurements, the nanocrystallization process corresponds to a three-stage crystallization model. The crystallization onset temperature of the amorphous alloy was observed to be to equal540 °C. The Curie point and saturation magnetization of the as-quenched alloy were defined as 305 °C and 76 Am 2 /kg, respectively.

The property of directional power absorption from a microwave magnetic field in thin anisotropic magnetic films was demonstrated. They are 2D printed magnetic nanoparticle chains on polyethylene foil (LDPE) made of single-domain Fe3O4 magnetic nanoparticles with magnetic uniaxial anisotropy. The 2D feature of the magnetic material results from the self-assembling of magnetic nanoparticles into ring-shaped chains during the drying of the magnetic colloid droplet on LDPE. Ferromagnetic resonance experiments on such thin magnetic films showed the possibility of selective dissipation of microwave magnetic field power. The experimental results were supported by computer simulations using Landau-Lifshitz-Gilbert equations. The possibility of directional power loss in the absence of a static magnetic field was also briefly discussed. (c) 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/)

It can be observed that magnetic iron-oxide nanoparticles are increasingly used in bioassay methods. This is due to their stability in aqueous solutions, ease of functionalization, biocompatibility and very low toxicity. Here, we show that the recent discovery of the ability of magnetic nanoparticles to self-assemble into 2D structures of ordered chains may be exploited for bioassays. This would open up the possibility of controlled immobilization of proteins, enzymes, DNA or RNA and other molecular systems on spatially ordered nanostructures. In this work, fluorescein was used as an example. Also shown is the possibility of using Raman spectroscopy to analyze material accumulated on such structures. The observed formation of regularly spaced chains of magnetic nanoparticles takes place during the drying process of a thin layer of magnetic liquid placed on an appropriately prepared low-density polyethylene (LDPE) film.

The sessile drop method was used to measure temperature dependencies of the surface tension and density of Cu-Pb and Ga-Pb melts. Ther obtained dependencies and results were analysed and interpreted. It let us claim the significant influence of Pb on the surface tension values and density of the investigated alloys. The atomic distribution in both alloys is characterized by a tendency to like-kind atoms interaction. The obtained result shows good agreement with the literature data.

The investigation addresses the structure of a Co-based alloy and its magnetic properties. The major applications of these materials are in the development of different sensors, which require materials with high permeability. The structure evolution processes need to be explored to clarify the main parameters determining the time-temperature stability. In the present paper, a nanocrystallization behavior of Co67Fe4Cr7Si8B14 amorphous alloy manufactured in the form of a ribbon was studied using X-ray diffraction and sample vibromagnetometry methods. The structure evolution induced by the 30min isothermal annealing at a temperature range of 450 - 700 °C was studied by the X-ray diffraction method, and crystallization with hcp-Co, fcc-Co, and Co2B nanophases was revealed depending on the annealing temperature. According to thermomagnetic measurements, the nanocrystallization process corresponds to a three-stage crystallization model. The crystallization onset temperature of the amorphous alloy was observed to be to equal540 °C. The Curie point and saturation magnetization of the as-quenched alloy were defined as 305 °C and 76 Am2/kg, respectively.

The paper investigates the process of liquid-phase sintering of amorphous iron-based nanoparticles by the method of molecular dynamics simulations. The classical molecular dynamics package LAMMPS was used for modeling. Visual analysis of the atomic configurations of nanoparticles during their rapid cooling revealed the self-purification effect of the particles. Partial pair correlation functions and coordination number distribution functions were used to analyze the atomic structure of nanoparticles after sintering. As a result of the analysis of the main structural parameters, which were obtained using the specified functions, differences in the atomic composition and structure of the volume and surface of nanoparticles were established.

In this work, the possibility of using low-power laser radiation to obtain bulk amorphous alloys by the method of selective laser melting was studied. For this purpose, the effect of laser radiation with a power of 15, 25 and 40 W on the surface morphology and structure of Fe86B14 amorphous ribbons and powders was studied. Irradiation was carried out at scanning speeds of 1000, 2000 and 4000 mm/s for each laser power mode. The result of laser treatment was studied by the methods of X-ray diffraction and scanning electron microscopy. The research made it possible to determine the optimal processing parameters for obtaining a bulk alloy with the maximum amount of the amorphous phase.

The atomic structure at the boundary of two phases (liquid-gas, liquid-crystal) is an important factor that affects the course of physical processes associated with the sintering of powder materials by both classical methods and the use of additive technologies. In this regard, the atomic structure of surface thin layers at the liquid-gas and liquid-crystal interfaces for densely packed metals (Al, Cu) and silicon, which are usually the main components of light structural materials, is studied in this work. The computer simulation method was used to obtain the atomic configurations of the studied materials. Structure analysis was carried out using two-dimensional and three-dimensional pair correlation functions, as well as distributions of coordination numbers and relative free volume. As a result of the work, the main regularities of the formation of the surface atomic structure of materials depending on the temperature around the melting point were established. In particular, it is shown that for the case of all studied materials, the melting process begins within three or four surface atomic layers. Studies of the free volume of the surface of materials depending on the distance to the interface indicate a significant amount of it at the liquid-gas interface. This feature obviously contributes to the intensification of surface diffusion, which becomes more important in the case of two-component and multi-component systems. The temperature dependence of the coordination numbers depending on the distance to the surface, as well as the analysis of interatomic distances, indicate a decrease in the degree of ordering of atoms with distance from the silicon surface.

Electrical current annealing based on the Joule-heating technique, known also as the thermal electrical resistivity method, was applied for nanocrystallyzation of the Fe 73.5 Nb 3 Cu 1 Si 15.5 B 7 amorphous ribbon. The feature of the Joule-heating technique is high heating rates of the material internal volume that in the case of amorphous alloys causes the evolution of the metastable amorphous state. Structure transformation was investigated by the X-ray diffraction method, which allows obtaining the phase composition of the material as well as nanograin size. The nanocrystalline phases that precipitate during current annealing are Fe 3 Si and hexagonal phase with a nanoscale grain size, the average value of which tends to depend on annealing duration as well as applied voltage and varies in the range of 10–200 nm. Field-emission scanning electron microscopy was used to investigate the surface topology and nanograins, and at some samples, petal-like structures were observed on the ribbon’s surface after the Joule-heating technique application. Saturation magnetization and microhardness were studied in relation to electrical current parameters, and optimal values were observed for its improvement. Obtained results could be helpful for controlling the conditions of the formation of fully or partially nanocrystalline structured materials from amorphous ribbons based on Fe-Si-B-Nb-Cu.

The magnetic properties of the amorphous Co57Fe5Ni10Si11B17 alloy have been studied by a vibrating sample magnetometer. The temperature dependence of saturation magnetization was measured and the Curie point and crystallization onset temperature were determined as 560 K and 760 K respectively. The coercive force was obtained as 200 A/m and saturation magnetization - 65 Am2 /kg. The alloy was produced in the form of a ribbon thickness of 30 µm using the melt spinning method, and its internal amorphous structure was examined by the X-ray diffraction method. The crystallization behavior of the alloy was studied using series of isothermal annealing of the samples of the alloy at temperatures in the range of 723-1023 K for different exposures (up to 240 minutes) and nanocrystalline phases were detected by the X-ray diffraction analysis.

The structure evolution of amorphous metallic alloys during different kinds of thermal effects is an important problem of disordered systems physics. A precise evolutional model would allow predicting the formation of such a structural state, providing the necessary physical and mechanical alloy properties.The paper is devoted to the problem of modelling the explosive crystallisation process in metal glasses induced by laser, supplemented by experimental results.A theoretical model of laser-induced explosive crystallisation in metal glasses is proposed. A pulse laser heating method for the surface processing was developed, making it possible to obtain two-layer structures with an adjustable thickness of the amorphous crystalline layer.The proposed model is assumed to test and optimes for metal glasses of other chemical compositions.A theoretical model of laser-induced explosive crystallisation in metal glasses allows for predicting and controlling structure changes to obtain the desired properties.The investigation of structure changes at rapid heating of amorphous alloys by experimental methods is very limited in obtaining data and their interpretation. For that reason, combining the modelling with experimental measurements is proposed. The results of this work have value for a scientist in material science, physics and engineering, which use nonequilibrium physical processes to obtain new materials, including nanoscale systems.