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Chemical polymerization of aniline was carried out in aqueous solutions of sulfonated polysulfone (SPS) at different concentration ratios of aniline and SPS sulfo groups. The polymerization progress was investigated by in situ spectroscopy in the UV–visible–near-IR region. It has been shown that, with increasing concentration of SPS, the rate of polymerization increases. Films of water-dispersible complexes of polyaniline (PANI) with SPS were obtained by spray coating. The electronic and chemical structure, morphology and sensory (ammonia) properties of films of PANI–SPS complexes were studied for the first time. [ABSTRACT FROM AUTHOR]

The morphological characteristics of the surface of a number of films of elastomers based on polyurethanimides (PUI) were studied by atomic force microscopy (AFM). Significant differences in the surface morphology of PUI films were found depending on the composition: from granular morphology with different grain sizes or spongy morphology with nano - and submicron pores and cavities on the surface, to spherulitic morphology. It is shown that the roughness of the free surfaces formed during the films formation from the solution is significantly lower than the roughness of the surface which was in contact with the substrate. The influence of the chemical structure and size of the rigid diamine fragments in PUI macromolecules on the morphology of the film surface and the presence of different phases in the AFM torsion mode is established. The comparison of the deformation and strength characteristics showed high values of the elongation at break (more than 1400%) in the PUI films with a developed porous structure of both surfaces. The results obtained show the need to control and take into account the morphological parameters of the surface layers of products made of highly elastic imide-containing materials for their use for technical and other purposes. [ABSTRACT FROM AUTHOR]

Abstrac: Composite coatings containing iodine- and bromine-containing compounds as biocides have been obtained on the basis of industrial paintwork materials. A number of composite coatings containing biocides – Nitroxynil, Ioxynil and 2,5-dibrom-4-nitrophenol, have been analyzed using a modified technique for assessing biological activity and toxicity for determining the survival rate of Artemia salina crustaceans. It was found that the compositions on the basis of paintwork materials with Nitroxynil show the greatest bioactivity. AFM study of the surface morphology of the developed coatings showed that the introduction of biocides leads to coating structuring at the nanolevel, with the strength of nanostructured coatings on impact decreases by 2–3 times, however, these values are 2 times higher than those of the reference sample – an industrial copper-containing antifouling paint. The obtained results can be used for further development of environmentally safe protective and antifouling polymer coatings and paintwork materials. [ABSTRACT FROM AUTHOR]

The optical properties, morphology, and structure of coatings from nanoparticles of rare-earth metals La, Nd, Pr, and Y, obtained by laser ablation with an Nd 3+:YAG laser in various media (air, distilled water), were investigated. It was established that the electronic absorption spectra of colloidal solutions of the studied nanoparticles have maxima in the UV and visible regions. The optical density of the solutions varied from 0.2 to 1.6 with an absorbing layer thickness of 10 mm and under identical excitation conditions at a wavelength of 1064 nm. The sizes of the nanoparticles of the rare-earth metals and the micromorphology of the deposited coatings in atmospheric and aqueous media were investigated by atomic-force microscopy. It was shown that the deposited nanostructures of the investigated metals have various morphologies and differ in the form and size of the nanoparticles depending on the deposition medium. [ABSTRACT FROM AUTHOR]

The surface morphology, structural organization, and transport properties of composite membranes based on Russian Nafion-type perfluorinated copolymers filled with zirconium dioxide nanoparticles are studied using atomic force and scanning electron microscopy, X-ray structural analysis, and thermal analysis. A relationship between the morphology of the free surface and the "substrate" surface of Nafion-LSC-1 proton-conductive film membranes and the concentration of zirconium-dioxide nanoparticles (ZrO2) is found. Atomic force and scanning electron microscopy reveals a gradient in the concentration of zirconium-dioxide nanoparticles, with the highest concentration on the substrate side of the membrane. The free surface is characterized by the presence of two phases alternating over the surface area of the membrane, which may be due to the presence of hydrophilic and hydrophobic regions. Zirconium nanoparticles form associates with sizes up to 300 nm. Wide-angle X-ray diffraction data suggest that Nafion-LSC-1 composite membranes have a mesomorphic structure when the concentration of zirconium-dioxide nanoparticles is 1.6 wt %, while the precursors of these membranes are characterized by a crystalline structure. The samples of Nafion-LSC-1 and composite membranes filled with 0.53, 1.12, and 1.61 wt % of nanoparticles are characterized by moisture content, proton conductivity, and heat resistance. [ABSTRACT FROM AUTHOR]

The photoinduced crystallization of thin amorphous films based on the binary compound Sb2Se3 and the ternary compound Ge2Sb2Te5 under continuous-wave laser irradiation is studied. The optical parameters of amorphous and crystalline films are analyzed by optical and atomic force microscopies, ellipsometry, spectrophotometry, and Raman spectroscopy. The crystallization temperatures, optical band gaps, Urbach-tail lengths, the activation energies of electrical conductivity, as well as the spectral dependences of the refractive indices and the extinction coefficients, are determined. The crystallized regions of Sb2Se3 are characterized by the more pronounced inhomogeneity of reflectivity (grain size) compared to crystalline regions of Ge2Sb2Te5 produced with the same laser-beam parameters. An analysis of the topography of crystallized films shows qualitative differences in the crystallite sizes. The distinctions may be related to differences in the mechanism of photoinduced crystallization. The Sb2Se3 compound has a higher optical band gap in comparison with Ge2Sb2Te5 and lower absorbance in the visible and near-infrared region, which can reduce the optical losses in the elements of silicon integrated optics based on the phase-change materials, as well as extend the range of possible application of phase-change materials for optical elements and nanophotonics devices. [ABSTRACT FROM AUTHOR]

The influence of the reflective facet parameters, primarily its camber, on the diffraction efficiency of perfect silicon gratings with blaze angles of 3°–4° and a groove density of 500 and 250 mm–1, which are intended for operation in soft X-ray and extreme UV radiation, is studied. The investigated diffraction gratings are fabricated by the wet etching of Si (111) vicinal wafers and characterized by atomic-force microscopy to determine the relief of the grooves. For one of the considered gratings with a Mo/Si multilayer coating, a record-breaking absolute efficiency of ~40% at a wavelength of 13.5 nm in the –8th order of unpolarized radiation was obtained recently. The possibility of achieving high efficiencies of high diffraction orders, with a number of ~10 and more is considered; this means the possibility of unique X-ray echelle fabrication. An estimate of the influence of the introduced camber parameter of the reflected facet on the maximum achievable order number of highly efficient diffraction is obtained. The absolute and relative (grating) efficiencies are determined by simulation using the PCGrate™ code based on the method of boundary integral equations and groove profiles measured using atomic-force microscopy. [ABSTRACT FROM AUTHOR]

The nature of cathodic polarization in an iridium-plating electrolyte based on a sulfamate solution of H2[IrCl6] was studied. Spectroscopic analysis shows that the iridium electrolyte contains binuclear oxygen-bridged Ir(III, IV) sulfamate complexes. The microstructure and distribution profiles of the iridium deposit in contacts of different diameters were studied. The structure of the iridium deposit is highly dispersed. The nonuniformity of the iridium deposit profile over the contact area and the dependence of the deposit thickness on the contact diameter can be reduced by varying the hydrodynamic conditions of the metal electroplating (stirring of the electrolyte with a magnetic stirrer or ultrasound) and by using electrochemical polarization. The Ir–GaAs contacts with the Schottky barrier are characterized by high quality of electrophysical parameters and good reproducibility of the volt–ampere characteristics. A decrease in the thickness of the iridium deposit and of the n-GaAs epitaxial layer leads to an increase in the barrier height of the rectifying Ir–GaAs contacts. [ABSTRACT FROM AUTHOR]

Modern-day chip manufacturing requires precision in placing chip materials on complex and patterned structures. Area-selective atomic layer deposition (AS-ALD) is a self-aligned manufacturing technique with high precision and control, which offers cost effectiveness compared to the traditional patterning techniques. Self-assembled monolayers (SAMs) have been explored as an avenue for realizing AS-ALD, wherein surface-active sites are modified in a specific pattern via SAMs that are inert to metal deposition, enabling ALD nucleation on the substrate selectively. However, key limitations have limited the potential of AS-ALD as a patterning method. The choice of molecules for ALD blocking SAMs is sparse; furthermore, deficiency in the proper understanding of the SAM chemistry and its changes upon metal layer deposition further adds to the challenges. In this work, we have addressed the above challenges by using nanoscale infrared spectroscopy to investigate the potential of stearic acid (SA) as an ALD inhibiting SAM. We show that SA monolayers on Co and Cu substrates can inhibit ZnO ALD growth on par with other commonly used SAMs, which demonstrates its viability towards AS-ALD. We complement these measurements with AFM-IR, which is a surface-sensitive spatially resolved technique, to obtain spectral insights into the ALD-treated SAMs. The significant insight obtained from AFM-IR is that SA SAMs do not desorb or degrade with ALD, but rather undergo a change in substrate coordination modes, which can affect ALD growth on substrates. [ABSTRACT FROM AUTHOR]

The problems of growing short-period InAs/GaSb superlattices on GaSb (100) substrates by molecular-beam epitaxy are studied. For InAs/GaSb epitaxial heterostructures, a method for forming "InSb-like" atomically smooth interfaces with an ultrathin intermediate In(As)Sb layer is developed. This technique allowed growth of a short-period superlattice containing 50 InAs/GaSb periods. In situ growth control using high-energy electron diffraction and post-growth studies of the superlattice using atomic-force microscopy and X-ray diffraction confirm the efficiency of the technique for fabricating detector structures based on type-II superlattices. [ABSTRACT FROM AUTHOR]

The results of studying the morphology and crystalline, local atomic, and chemical structure of iron(III) oxide coatings on the surface of porous aluminum oxide with different morphology using methods of scanning-electron- and atomic-force microscopy, X-ray phase analysis, X-ray photoelectron spectroscopy, as well as X-ray absorption near edge structure (XANES) spectroscopy are presented. Films of porous alumina are synthesized by the two-stage anodic oxidation of aluminum in 0.3 M aqueous solutions of sulfuric and oxalic acids. To change the pore diameter, some of the films are etched in a phosphoric-acid solution. Samples of iron oxide nanocoatings are obtained by oxidation of iron films in air deposited onto porous alumina substrate matrices by magnetron sputtering at a temperature of 300°C for 3 h. It is shown that oxidation leads to a twofold increase in the coating thickness of the control sample and is associated with an increase in the density of iron oxide compared to pure iron. With a change in the nanoporous structure on the surface of the substrates, the morphological features of the coatings change: there is overgrowth of the pores with iron oxide. Controlling the processes leading to such overgrowth will make it possible to carry out a targeted change in the structure-sensitive properties of composite structures based on iron oxide. [ABSTRACT FROM AUTHOR]

We present the results of the luminescence response studies of a single YVO4:Yb, Er particle of 1-µm size. Yttrium vanadate nanoparticles are well-known for their low sensitivity to surface quenchers in water solutions which makes them of special interest for biological applications. First, YVO4:Yb, Er nanoparticles (in the size range from 0.05 µm up to 2 µm), using the hydrothermal method, were synthesized. Nanoparticles deposited and dried on a glass surface exhibited bright green upconversion luminescence. By means of an atomic-force microscope, a 60 × 60 µm2 square of a glass surface was cleaned from any noticeable contaminants (more than 10 nm in size) and a single particle of 1-µm size was selected and placed in the middle. Confocal microscopy revealed a significant difference between the collective luminescent response of an ensemble of synthesized nanoparticles (in the form of a dry powder) and that of a single particle. In particular, a pronounced polarization of the upconversion luminescence from a single particle was observed. Luminescence dependences on the laser power are quite different for the single particle and the large ensemble of nanoparticles as well. These facts attest to the notion that upconversion properties of single particles are highly individual. This implies that to use an upconversion particle as a single sensor of the local parameters of a medium, the additional studying and calibration of its individual photophysical properties are essential. [ABSTRACT FROM AUTHOR]

Accelerated cluster ions formed during the outflow of inert gases are a unique tool for the precision surface treatment of various materials, including nonlinear optical single crystals. However, the interaction of gas cluster ions with the surface of nonlinear single crystals has been little studied. In this paper, we consider the features of the formation of anomalous craters during treatment of the surface of hygroscopic lithium-triborate single crystals with argon cluster ions at various bombardment doses. The treatment is carried out at a kinetic energy of clusters of 22 keV, an average cluster size of about 210 atoms per cluster at a normal angle of incidence. It is shown that the anomalous craters have a diameter of 150 to 820 nm, which are two orders of magnitude larger than the diameter of ordinary impact craters. The depth of the craters varies from 5 to 9 nm. Such craters are formed at a target etching depth of up to 320 nm. A statistical analysis of the geometrical parameters of anomalous craters is carried out at various treatment doses. It is established that with an increase in the irradiation dose and, accordingly, the etching depth, the density of anomalous craters per unit surface of the target decreases, while their depth and average diameter increase significantly. [ABSTRACT FROM AUTHOR]

The influence of heat treatment on the distribution of lithium over the depth of surface layers is studied for rapidly solidified foils of industrial Al–Mg–Li–Sc–Zr alloy (1421) produced by ultra-rapid quenching from the molten state using unilateral cooling on the internal surface of a rotating copper drum. It is found by electron backscatter diffraction that the as-cast foils had a micrograin structure with an average grain size of 12 μm and the [111] texture. Using atomic-force microscopy, it is determined that the air-side surface is characterized by a fine cellular structure, which is also observed in the area of caverns and cavities on the drum-side surface. The surface roughness of the foils is from 44 to 57 nm. The patterns of the lithium depth distribution in the annealed samples are established by nuclear-reaction analysis using a proton-induced reaction (p, α). It is found that during low-temperature annealing, the surface and deep layers of the samples are depleted of lithium, which is evenly distributed over the foil depth. A multiple increase in the lithium concentration found in the surface region of the foils is established during high-temperature annealing, resulting in the formation of a composition-gradient foil structure. The effect of the structure and phase changes caused by the decomposition of a supersaturated solid solution with the precipitation of lithium-containing phases on the behavior of lithium in the annealing temperature range 150–380°C is discussed. [ABSTRACT FROM AUTHOR]

We explore the specific features of the surface state that determine the domain structure, magnetic properties and magnetic loss upon magnetization reversal of ribbon amorphous Fe(Ni,Cu)(SiB) alloys obtained by ultrafast cooling by melt sputtered onto a rotating drum. We use scanning electron microscopy, atomic-force microscopy, and magnetic-force microscopy and measurements of the magnetic characteristics before and after treatment by pulses of a weak magnetic field (10–100 kA/m) of low frequency (10–20 Hz). Both foil surfaces are studied. The surfaces of the samples adjacent to the copper drum had an inhomogeneous structure, typical of all rapidly hardened samples. The other sides of the foils are smoother, which make them look shiny. Atomic-force microscopy shows no changes in the surface structure of the foils after their magnetic-pulse processing. Changes are detected in the images of the shiny side of the samples, obtained by magnetic-force microscopy. No domain structure is observed in the samples before magnetic-pulse processing. After magnetic-pulse treatment, stripe domains with a width of 0.6–0.8 nm and closure domains with a width of 1.0–1.6 nm are found at structural defects, and a weak magnetic contrast as large and small domains with a shape close to triangular is detected in some areas of the surface. The magnetization-reversal loss is largely related to the loss caused by eddy currents and is affected by the domain width (about 1.5 nm), which depends only slightly on the modes of magnetic-pulse processing. The results can be used to refine the procedure for relieving stress arising during the manufacturing of amorphous ribbons. [ABSTRACT FROM AUTHOR]

Amphiphilic molecular brushes or graft copolymers (graft-CPs) with a hydrophobic polyimide main chain and hydrophilic side chains of polymethacrylic acid at a high degree of polymerization m of the side chains and their high grafting density can be used as nanocontainers for the targeted delivery of drugs/agents. In this work, silver nanoparticles (Ag0) or selenium nanoparticles (Se0) in zero-valent form, which have a complex of unique biomedical properties, are used as the loading agent. Using ultraviolet (UV)–visible spectroscopy, atomic-force microscopy, and transmission electron microscopy, aqueous dispersions of Ag0 and Se0 nanoparticles stabilized by amphiphilic molecular brushes of varying topology are compared. The structural-morphological and spectral parameters of Ag0/graft-CP and Se0/graft-CP nanostructures can be controlled by changing the degree of polymerization m of side chains of the graft copolymer. [ABSTRACT FROM AUTHOR]

La-doped nanostructured NiO films are fabricated by the sol-gel spin-coating technique on a fluorine-doped tin-oxide glass. The atomic-force microscopy of La : NiO films demonstrates a change in the grain size of the film due to doping with La. X-ray diffraction shows that La : NiO films are of a nanocrystalline nature, the crystallite size decreases as the La content increases. The optical constants are calculated by the Kramers–Kronig method. The band gap decreases at a higher La dopant content due to the quantum-confinement effect. The values of the nonlinear susceptibility of the films of first and third orders are also calculated, and these parameters behave in a similar way. A highly effective radiation-protective material based on La : NiO films is obtained. [ABSTRACT FROM AUTHOR]

Europium-doped silicate sol–gel glass materials with Cu2Se nanoparticles are studied by small-angle neutron scattering and atomic-force microscopy. Based on the experimental data, the structural characteristics of both Cu2Se nanoparticles and density fluctuation regions of the glass matrix are obtained. A change in the Eu concentration is found to have almost no effect on the morphology and size of Cu2Se nanoparticles. However, local changes were observed in the structure of glass density heterogeneities. Possible structural mechanisms for the formation of such composite nanomaterials of complex composition are discussed. [ABSTRACT FROM AUTHOR]

Modern-day chip manufacturing requires precision in placing chip materials on complex and patterned structures. Area-selective atomic layer deposition (AS-ALD) is a self-aligned manufacturing technique with high precision and control, which offers cost effectiveness compared to the traditional patterning techniques. Self-assembled monolayers (SAMs) have been explored as an avenue for realizing AS-ALD, wherein surface-active sites are modified in a specific pattern via SAMs that are inert to metal deposition, enabling ALD nucleation on the substrate selectively. However, key limitations have limited the potential of AS-ALD as a patterning method. The choice of molecules for ALD blocking SAMs is sparse; furthermore, deficiency in the proper understanding of the SAM chemistry and its changes upon metal layer deposition further adds to the challenges. In this work, we have addressed the above challenges by using nanoscale infrared spectroscopy to investigate the potential of stearic acid (SA) as an ALD inhibiting SAM. We show that SA monolayers on Co and Cu substrates can inhibit ZnO ALD growth on par with other commonly used SAMs, which demonstrates its viability towards AS-ALD. We complement these measurements with AFM-IR, which is a surface-sensitive spatially resolved technique, to obtain spectral insights into the ALD-treated SAMs. The significant insight obtained from AFM-IR is that SA SAMs do not desorb or degrade with ALD, but rather undergo a change in substrate coordination modes, which can affect ALD growth on substrates.

Electrochemical polymerization of 3,4-ethylenedioxythiophene (EDOT) in the presence of water-soluble sodium salt of zinc octa(3′,5′-dicarboxyphenoxy)phthalocyaninate containing 16 ionogenic carboxylate groups is studied. By using electrochemical and spectral methods of monitoring the course of the electrosynthesis the EDOT polymerization in the presence of phthalocyaninate is shown to proceed at higher rate compared to that in the presence of low-molecular electrolyte (sodium acetate). The electropolymerization acceleration is discussed in terms of templating effect of locally-ordered carboxylate groups of phthalocyaninate in analogy with the EDOT template electropolymerization in the presence of polyelectrolytes. Electronic and chemical structures, morphology, spectroelectrochemical and sensor properties (with respect to ammonia) of the PEDOT composite films obtained in the presence of water-soluble phthalocyaninate are studied for the first time. [ABSTRACT FROM AUTHOR]

The HeLa cell's nuclei surface landscape, which appeared after the mechanical deformation, was studied by atomic-force microscopy. Nuclei were isolated from HeLa-line cells, and deformed under centrifugal forces, followed by fixation with glutaraldehyde. The resulting landscape was shown to be mainly due to the high chromatin resistance to deformation. This stability correlates with DNA supercoiling. Cells' treatment with topoisomerase inhibitors I and II leads to the relaxation of supercoiling and significant flattening of the nuclei. On the contrary, cells' treatment with a DNA intercalator leads to an increase in the DNA rigidity and, as a result, the resistance of chromatin to mechanical deformation. Thus, the observed changes in morphology reflect the functional features of the cell nucleus. [ABSTRACT FROM AUTHOR]

Skin barrier function (SBF) disorders are a class of pathologies that affect a significant portion of the world population. These disorders cause skin lesions with intense itch, impacting patients' physical and psychological well-being as well as their social functioning. It is in the interest of patients that their disorder be monitored closely while under treatment to evaluate the effectiveness of the ongoing therapy and any potential adverse reactions. Symptom-based assessment techniques are widely used by clinicians; however, they carry some limitations. Techniques to assess skin barrier impairment are critical for understanding the nature of the disease and for helping personalize treatment. This review recalls the anatomy of the skin barrier and describes an atomic-force microscopy approach to quantitatively monitor its disorders and their response to treatment. We review a panel of studies that show that this technique is highly relevant for SBF disorder research, and we aim to motivate its adoption into clinical settings., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Nanoclusters of metals and metal-oxide compounds in various solid-state matrices can find application in promising microelectronic devices. The results of studying memristors based on silicon-oxide films implanted with 64Zn+ ions (dose of 3 × 1016 cm–2 and energy of 40 keV) at room temperature and annealed at temperatures from 400 to 800°C in an oxidizing environment are presented. The concentration profiles of implanted zinc, as well as matrix elements, silicon and oxygen, are obtained via the Rutherford backscattering spectroscopy of He+ ions with an energy of 2 MeV. The surface topology is investigated using a scanning probe microscope in the atomic-force-microscopy mode and Kelvin mode. After implantation, sample-surface smoothing occurs due to sputtering. Further, during thermal annealing, the surface roughness increases and broadening of the roughness distribution is observed in comparison with the implanted sample. The images of the surface potential obtained in the Kelvin mode differ in terms of the sign of the signal: positive, for the initial sample, and negative, for the sample annealed at 800°C. The phase composition of the films is studied using X-ray diffraction analysis in the grazing geometry. It is found that crystalline phase of Zn was formed in the SiO2 film after implantation. After annealing at 800°C, the Zn phase is mainly transformed into the zinc silicide (willemite) Zn2SiO4 phase and partially into the ZnO phase. The analysis of small peaks in the diffraction patterns carried out using the EVA program indicates that the β-Zn2SiO4 and Zn1.95SiO4 phases are formed in the samples. [ABSTRACT FROM AUTHOR]

We present the results of the luminescence response studies of a single YVO4:Yb, Er particle of 1-µm size. Yttrium vanadate nanoparticles are well-known for their low sensitivity to surface quenchers in water solutions which makes them of special interest for biological applications. First, YVO4:Yb, Er nanoparticles (in the size range from 0.05 µm up to 2 µm), using the hydrothermal method, were synthesized. Nanoparticles deposited and dried on a glass surface exhibited bright green upconversion luminescence. By means of an atomic-force microscope, a 60 × 60 µm2 square of a glass surface was cleaned from any noticeable contaminants (more than 10 nm in size) and a single particle of 1-µm size was selected and placed in the middle. Confocal microscopy revealed a significant difference between the collective luminescent response of an ensemble of synthesized nanoparticles (in the form of a dry powder) and that of a single particle. In particular, a pronounced polarization of the upconversion luminescence from a single particle was observed. Luminescence dependences on the laser power are quite different for the single particle and the large ensemble of nanoparticles as well. These facts attest to the notion that upconversion properties of single particles are highly individual. This implies that to use an upconversion particle as a single sensor of the local parameters of a medium, the additional studying and calibration of its individual photophysical properties are essential.

The synthesis of novel oligothiophene‐containing carbosilane‐siloxanes of linear or branched structure with conjugation lengths of 4–7 thiophene rings, flexible aliphatic spacers varying from C3 to C11, and various degrees of branching of end‐capping solubilizing groups is reported. The investigation of their phase behavior by differential scanning calorimetry and polarizing optical microscopy showed that although some of them can form liquid‐crystalline phases, the majority of the linear molecules exhibits a high degree of crystallinity, which decreases with increasing degree of branching. Aggregation studies in dilute solutions in toluene at different temperatures allowed determination of the temperature and concentration dependence of their dissociation. The investigation of thin films prepared from dilute solutions revealed the formation of fibril domains confirming aggregation of the molecules. [ABSTRACT FROM AUTHOR]

In atomic force microscopy, the interaction of a probe with a sample is usually controlled by the angle of cantilever bending at a selected point on it using an optical lever. Such control is not designed to record all three components of the interaction-force vector. It is possible to reveal these components and the result of the force action, i.e., the displacement vector of the "nondeformable" probe of an "ideal" cantilever, by additional measurements of the deformation (by the piezoresistive method) or the amount of bending (by the interferometry method) at a selected point, or the bending angle at one more point on the cantilever. In this paper, we present the results of analytical calculation of the optimal location of these points on a cantilever for six combinations of the above three methods, which reduces the measurement error of the components of the force and displacement vectors to a minimum. [ABSTRACT FROM AUTHOR]

A comparative study of newly synthesized copper- and selenium-containing nanosystems based on a wide range of water-soluble polymer stabilizers is carried out using atomic force and transmission electron microscopy. Bovine serum albumin, poly-4-acryloylmorpholine, water-soluble statistical copolymers of 2-deoxy-2-methacrylamido-D-glucose or 4-acryloylmorpholine with 2-dimethylaminoethyl methacrylate) are used as polymer stabilizers. The effect of the stabilizer and nanoparticle nature on the structural and morphological characteristics of the nanostructures/nanoparticles and the mechanism of their formation is revealed using copper- and selenium-containing nanosystems as an example. In an aqueous solution of the studied nanosystems, mainly spherical nanostructures/nanoparticles are formed, the size of which is primarily determined by the nature of the nanoparticles: copper-containing nanostructures/nanoparticles have a smaller size than selenium-containing ones. [ABSTRACT FROM AUTHOR]

Laser optoporation systems are now increasingly used for intracellular delivery. However, data on the response of cells to radiation-induced nondamaging changes in the integrity of the membrane lipid bilayer remain limited. Traditionally, confocal laser scanning microscopy and electron microscopy are used for such studies, but they have limitations for in situ experiments. The modern capabilities of atomic force microscopy (AFM) combine the resolution of electron microscopy and the possibility of noninvasive lifetime imaging of cells in vitro. Herein we used long-term AFM mapping integrated with fluorescence microscopy imaging for investigation of the whole cell cycle from irradiation time point to the total recovery to the intact cell state. For the first time we performed a comprehensive study of long-term posteffects of continuous laser and pulsed laser on the mechanical properties and the membrane recovery of HeLa cells grown on the Au nanoparticle layers of various morphologies. The set of nonpenetrating agents with various sizes ranging from 1 to 1.5 nm for propidium iodide (PI) up to 6–8 nm for 40 kDa FITC-labeled dextran was used to control the delivery efficacy. The main parameters recorded with AFM scanning of cells are Young's modulus (YM) and the cell surface topography. We revealed that self-healing of HeLa cell from the moment of irradiation to complete restoration of the membrane integrity is lasting 22–30 h when using a continuous-wave source and 2–5 h when using a pulsed laser, respectively. The estimated time elapse was in good correspondence with the relative change in YM during the entire experiment. Our findings demonstrate the capability of AFM coupled with fluorescent microscopy for further in situ investigations of the morphological and functional state of the cells exposed to the influence of other external conditions. [ABSTRACT FROM AUTHOR]

The results of studies of the effect of low-power He–Ne laser radiation at a wavelength of 632.8 nm on the surface morphology of ~1-μm-thick glassy (amorphous) Se films synthesized by vacuum thermal evaporation are reported. It is shown that, depending on the radiation intensity and the exposure time, the laser-induced modification of films is accompanied by different changes in their roughness and by the appearance of structures different in size and the phase composition on the film surface. The formation of submicron-ridge chains on the surface of the laser-modified films yields an increase in their reflectance and refractive index and a decrease in their optical thickness. [ABSTRACT FROM AUTHOR]

In this paper the surface of diffusion filter membranes of alloy Pd–5.3 at %–In–0.5 at % Ru is studied by atomic force microscopy. This alloy is in demand in the diffusion separation processes of high-purity hydrogen. The surface of membranes is studied before and after hydrogenation. Prior to hydrogenation, it is determined that the surface structure of the membrane alloy contains regions of a local increase in hardness. These regions are surrounded by a significant dislocation density. It is found that reversible hydrogen doping of the membrane alloy both from the gas phase and by the electrochemical method do not eliminate the presence of such regions. The dispersion of the surface structure of diffusion filter membranes is revealed and a large degree of surface changes is determined during electrochemical hydrogenation compared to gas-phase hydrogenation. [ABSTRACT FROM AUTHOR]

The surface morphology, elemental composition, and nanohardness of thin fullerite–aluminum films with different atomic fractions of metal are investigated by scanning electron and atomic-force microscopies, X-ray spectral microanalysis and nanoindentation. The films are obtained by the method of resistive evaporation in vacuum from a combined atomic-molecular flux of Al atoms and C60 molecules on single-crystal silicon substrates with the surface orientation (111). It is established that during deposition on unheated substrates, a nanocrystalline structure of films with an atomic fraction of metal of 20, 25 and 35%, with an average size of structural elements of 10, 15, and 25 nm, respectively, is formed. At the same time, internal mechanical stresses arise in the films, the relaxation of which leads to the exfoliation of significant sections of the film. During the deposition of films on substrates heated to 420 K, films with an average size of structural elements of 50–100 nm without exfoliation are formed, but in this case the nanohardness of the films decreases compared to the films obtained on unheated substrates. [ABSTRACT FROM AUTHOR]

Selection and optimization of the technological parameters of growth of Pb0.7Sn0.3Te layers with a thickness up to 300 nm grown on a Si(111) surface at a temperature of 230 to 400°C is carried out. The surface morphology of the resulting films is studied, and the epitaxial relations are determined. It is shown that, depending on the growth temperature, the surface morphology ranges from smooth micrometer-sized islands with monoatomic steps on their surface to narrower terraces. [ABSTRACT FROM AUTHOR]

By the atomic-force-microscopy method, the authors have studied the microstructure of coatings from tantalum and its compounds, which were formed on the surface of substrates from stainless steel and microscope slide by reactive magnetron sputtering. It has been established that nanostructured tantalum films are characterized by the cellular structure the size of whose cells depends on the material and the physicochemical properties of the substrate surface. [ABSTRACT FROM AUTHOR]

Spherical gold nanoparticles (NPs), 10 nm in diameter, have been dispersed in a type of polydimethylsiloxane, whose polymerisation requires accurate temperature control. At the temperature of 100°C, the polymerisation of the polydimethylsiloxane matrix is completed in 15 min, whereas at room temperature (∼20°C), it takes about 24–48 h. Gold NPs were incorporated into polydimethylsiloxane after which the resulting nanocomposites were placed in an oven preheated to 100°C for different curing times. Both porous and bulk nanocomposites were obtained using a bottom‐up approach. Polydimethylsiloxane (PDMS) nanocomposites with the weight‐percentage concentration of 0.2% of Au NPs were cured for 15, 30 and 45 min. Different curing times have affected the Au‐NP properties. The network of porous PDMS nanocomposite promotes a uniform anchoring of the gold NPs. The porous PDMS nanocomposite samples, prepared using the sugar‐template method, have been compared with the bulk counterpart to obtain a full characterisation of the material. The dependence of the morphological and electrical properties of gold NPs on their size has been studied by atomic‐force microscopy and two‐point‐probe electrical‐conductivity measurement. The optical performance of the bulk PDMS nanocomposites has been analysed by ultraviolet–visible (UV–vis) spectroscopy in the transmission mode. An enhancement of the absorption was observed after the increase of both the nanocomposite‐curing time and the percentage of the Au NPs used as fillers. The fabricated nanocomposite can be used to manufacture optical‐sensing devices, switches in optoelectronics and optical waveguides. [ABSTRACT FROM AUTHOR]

We study the influence of an antimony sublayer (10 nm) on the structure and galvanomagnetic properties of bismuth–antimony films with an antimony content of 3 and 5 at %, up to 1-µm thick, obtained by discrete vacuum evaporation, as well as films recrystallized by the zone-melting method. When using an antimony sublayer, blocks with a significant deviation of the trigonal axis from the normal to the film surface are revealed. The area of such blocks increases with increasing antimony concentration. In recrystallized films, when using a sublayer, the orientation of the trigonal axis is maintained perpendicular to the film plane and adhesion to the substrate is improved. Single-crystal films with an antimony sublayer are of interest for studying the possibilities of deformation engineering for modifying the band structure of thin, highly perfect films of bismuth–antimony solid solution in order to get the desired properties. [ABSTRACT FROM AUTHOR]

The intensity of light emitted by plasma and passing through diagnostic quartz windows in tokamaks and other fusion power devices may decrease due to first-wall materials (Be in the International Thermonuclear Experimental Reactor (ITER)) sputtered and re-deposited onto the window surface facing the plasma. In the experiments, aluminum films (analog of Be) are removed from the surface of fused silica KU-1 in plasma of a RF discharge in a H2–N2 mixture prototyping one of the in-situ cleaning techniques. The admixture of nitrogen to hydrogen plasma increases the sputtering rate of aluminum films. Using X-ray photoelectron spectroscopy (XPS) and atomic-force microscopy (AFM), we demonstrate that cleaning is accompanied by the weak reduction of quartz, nitriding with the addition of nitrogen, and the formation of a "honeycomb" structure with increased roughness. These processes are more pronounced with the repeated deposition of Al and subsequent cleaning. Light transmittance in the range 400–1000 nm does not change within 1% in the case of a partial change in the stoichiometry of the surface layers and an increase in the roughness from 1.3 to 4.5 nm. Numerical estimates of the forward and backscattering of light by a rough quartz surface show that the reduction in transmission due to scattering does not exceed a few tenths of a percent, which is in agreement with the measurement data. Thus, the demonstrated stability of the quartz transmittance during the deposition of aluminum and subsequent long exposure in the plasma of a RF discharge makes it possible to consider the cleaning technique under consideration promising for use in ITER. [ABSTRACT FROM AUTHOR]

The influence of electron-proton irradiation on the process of changing the surface structure of K‑208 glass, caused by the formation of gas-filled bubbles and their destruction, is studied by atomic-force microscopy (AFM). These phenomena are associated with the formation of hydrogen atoms H in the process of the recombination of protons with electrons injected into the glass and those that appeared in it during ionization. The migration of hydrogen atoms and their aggregation into H-clusters in the vicinity of glass structure defects leads to the formation of molecular hydrogen (H2) bubbles. The glass is exposed to electrons and protons with energies of 40 and 20 keV, respectively. Irradiation is carried out in a vacuum chamber with a residual pressure of 10–4 Pa. At a fixed value of the proton flux density φр = 5.5 × 1010 cm–2 s–1, the electron flux density φe varies in the range (0–16.8) × 1010 cm–2 s–1. It is shown that the size of the bubbles depends on the ratio of the parameters φe and φр. Analysis of the experimental data suggests that the destruction of a bubble occurs with a local decrease in the thickness of its cap to 10–20 nm, as a result of heating and growth in the direction normal to the surface under the pressure of the accumulating gas. It is also found that electrostatic discharges developing along the irradiated glass surface stimulate the destruction of bubbles. [ABSTRACT FROM AUTHOR]

Electron-beam treatment the glass substrates for sensitive elements of SPR devices causes almost two-fold narrowing their refractometric characteristics from 0.867 down to 0.453 deg. The angular shift was also changed, which made the measuring range wider by 0.37 deg. The sensitivity of SPR devices increased by 1.7 times from 1.425 up to 2.396 deg–1 as a consequence of lowering the energy expenses during propagation of surface plasmons along the boundary “metal–air”. The reason for this lowering is related to higher surface uniformity of the gold metal film, its higher density as well as lower nano-roughness of the glass surface and the thickness of heterointerface “gold–air”. In this case, the dispersion value for unevenness heights on the surface relatively to the base line was lowered from ±18 down to ±5 nm, mean-square roughness was three-fold reduced from 4.67 down to 1.64 nm, and the thickness of heterointerface gold–air was lowered from 3.26 down to 1.37 nm. It was ascertained using X-ray reflectometry that the film density increased from 17.2 up to 19.3 g/cm3 and reached the value typical for the bulk gold. It provided the changes in the refraction index and extinction coefficient of the gold film, which was ascertained using the ellipsometric method. Thus, the performed analysis of refractometric characteristics showed that electron-beam treatment the glass substrates of sensitive elements for SPR devices is able to efficiently enhance their sensitivity and to widen the range of measured resonance SPR angles.

An algorithm is considered for the statistical analysis of images of nanoparticles obtained by scanning probe microscopy, based on the harmonic analysis of surface profiles with a complex relief. Using harmonic analysis, the average sizes of particles are determined and the sizes of their aggregates are estimated. The algorithm enables the analysis of large samples of particles; in this work, it is tested using model natural objects with an ordered and disordered arrangement of nanoscale particles. The dependence of the analysis results on the type of particle size distribution is also considered, and the features of determining the average size for Gaussian and logarithmically normal distributions are revealed. Among the possible applications of the algorithm, we can mention analysis of the average size of particles and the value of their aggregation in microdispersed and nanodispersed structures (thin amorphous films, colloidal systems, noncrystalline substances, polymers) based on three-dimensional or pseudo-three-dimensional microscopic images. [ABSTRACT FROM AUTHOR]

Textured ZnO films obtained on amorphous substrates using the ion-beam sputtering method are studied. X-ray diffraction and atomic-force microscopy methods show that the resulting films have a polycrystalline structure immediately after deposition. It is established that further annealing of the samples in the temperature range from 200°C to 500°C results in recrystallization, which leads to changes in the grain size and surface roughness. A dependence of the crystallization intensity on the deposition conditions is found, which is related to the number of defects in the unannealed films. In films with an initially more perfect structure, heat treatment at 500°C results in the growth of grains by more than 2 times and a decrease in the roughness by ∼40%. [ABSTRACT FROM AUTHOR]

Arrays of magnetic nanocontacts are fabricated by growing Fe island films and filling the space between the islands with antiferromagnetic layers. The magnetic structures of the islands and their dependences on their dimensions are studied using atomic-force microscopy and micromagnetic calculations. Micromagnetic numerical calculations of the influence of the spin-polarized current flowing from the ferromagnetic edge into the antiferromagnetic interlayer on magnetization in magnetic antiferromagnet sublattices are carried out. The magnetization skew angle in magnetic antiferromagnet sublattices is found as a function of the current density. [ABSTRACT FROM AUTHOR]

We use atomic-force microscopy, transmission electron microscopy, ultraviolet (UV)/visible spectroscopy, and dynamic light scattering to perform a comparative study of new hybrid bioactive nanosystems based on nanoparticles of various natures: zero-valent copper (Cu0), zero-valent selenium (Se0), and zero-valent silver (Ag0) stabilized with a water-soluble homopolymer poly-4-acryloylmorpholine (PAM). We demonstrate the possibility of regulating the structural and morphological parameters and the dimensional and spectral characteristics of bioactive nanosystems by varying the nature of nanoparticles. The reduction of ions of biogenic elements in water in the presence of poly-4-acryloylmorpholine, due to sufficiently good screening, yields spherical nanostructures with a diameter not exceeding 180 nm (PAM/Se0). The most probable sizes of nanoparticles do not exceed 12 nm. [ABSTRACT FROM AUTHOR]

The soft zone in dentine beneath the dentino-enamel junction is thought to play an important role in tooth function, strain distribution and fracture resistance during mastication. Recently reported asymmetry in mechanical properties with tooth side may point at a basic property of tooth function. The aim of our study was to test if this asymmetry was reflected in the nano- and micromechanical properties of dentine. We investigated the mechanical properties of dentine on the buccal and lingual side of nine extracted human teeth using nano- and microindentation. Properties were analysed on the natural log scale, using maximum likelihood to estimate the parameters. Two-sided 0.05-level likelihood ratio tests were used to assess the influences of surface (buccal versus lingual) and dentine depth, measured from the DEJ in crown dentine and from the CDJ in root dentine. Results showed the well known gradual increase in mechanical properties with increasing distance from the DEJ. Coronal dentine showed higher elastic modulus and hardness on the lingual side of teeth for all measurements, while root dentine was harder on the buccal side. Due to the subtlety of these effects and the small number of teeth studied, results failed to reach statistical significance. Results suggest that dentine nano- and micromechanical properties vary with tooth side in agreement with recent literature using macroscopic methods. They also reveal that buccal-lingual ratios of hardness are in opposite directions in crown and root dentine, suggesting compensatory functions.

Subject of Research.We developed additives to shampoos based on different nature nanoparticles with micro- and nanoscale spatial resolution. The effect of the obtained nano-additives on the surface structure of hair fibers were studied. The aim of this work was to fabricate additive complexes of nanoparticles with various nature for shampoos and study of their effect on the hair cuticle structure by optical and atomic-force microscopy. Methods. The methods of chemical separation of elements, centrifugation, laser ablation, optical and atomic-force microscopy were used in the work. Main Results. The various types of hair structures were studied, such as normal, greasy, dry and animal hair, using optical and atomic-force microscopes. Сolloidal solutions of metals and their compounds were prepared (Ag, Au, Cu, Fe, Zn, Si, S, MoO3). Two types of additives for shampoos were fabricated: for greasy/normal and dry hair. The effectiveness of fabricated shampoo additives with complexes of different nature nanoparticles was shown. Practical Relevance. The development of new shampoos with the complexes of nanoparticles will increase the effectiveness of traditional types of shampoos, in particular, the recovery and maintenance of normal hair structure

The electrochemical codeposition of nickel with the dispersed molybdenum oxide of layered structure yields metalmatrix composites in which the second phase is capable to play a role of container retaining organics in its internal volume. It is shown that the intercalation of benzotriazole (a well-known corrosion inhibitor) into the interlayer volume of MoO3 ensures an effective suppression of tribocorrosion of matrix metal.

The results of studies of the surface morphology, electrical characteristics, and photoluminescence properties of epitaxial GaAs films grown by molecular-beam epitaxy on GaAs(110) substrates and doped with Si are reported. A series of samples is grown at a temperature of 580°C with the arsenic/gallium flow ratio in the range from 14 to 80. By analyzing the photoluminescence spectra of the samples, the behavior of Si atoms in GaAs is interpreted with consideration for the occupation of Ga or As sites by Si atoms (i.e., for the formation of SiGa and SiAs point defects) and the formation of vacancies of arsenic and gallium VAs and VGa. In the analysis, the photoluminescence spectra of the samples on (110)-oriented substrates are compared with the photoluminescence spectra of similar samples on (100)- and (111)A-oriented substrates. [ABSTRACT FROM AUTHOR]