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The morphology, structure, and optical properties of a composite material based on gold nanoparticles and thin film of amorphous nonstoichiometric silicon oxide (a-SiOx, x = 1.8) have been studied for the first time. Based on the obtained experimental data, it is established that a-SiO1.8 layer provides conformal coating of spherical nanoparticles. An analytical model based on the Mie theory adequately describes the experimental optical properties of gold nanoparticles and composite material in the UV spectral range, as well as the observed variation of the plasmonic peak amplitude during the formation of the composite material.

The method of hot-wire activated chemical vapor deposition (HW CVD) of fluoropolymer films has been adapted to obtain fluoropolymer coatings on rotating cylindrical surfaces of small radius (below 20 mm). The influence of the substrate rotation speed on the structure of thin fluoropolymer deposit was studied and revealed significant dependence of the coating morphology on the speed of cylindrical surface rotation, which is an additional parameter that can be used to control the structure of fluoropolymer coating during the HW CVD process.

Annealing of amorphous TiO2 nanotubes has been performed by nano-, pico- and femtosecond lasers. Only picosecond high-power laser of the HiLASE Centre enabled achieving crystallization into anatase phase via explosive solid-phase crystallization at high throughput.

The paper presents the results of the Hot-Wire Chemical Vapor Deposition of fluoropolymer films from C3F6O precursor gas, activated by NiCr wire catalyst mesh, at varying deposition process parameters. The temperature of activator wire is varied within the range of 580–900 °C, precursor gas pressure is changed within the range of 4–1333 Pa, and the temperature of the substrate is changed from 20 to 400 °C. The different surface structures of fluoropolymer coatings are obtained by changing the deposition parameters. The morphology and composition of the films and the growth rate were investigated by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy methods. We have measured contact angle, contact angle hysteresis, and surface free energy of the resulting fluoropolymer coatings. The surface structure of the coatings is shown to have a significant effect on the coating wettability. One of the main results is that the increasing of the activating mesh wire temperature leads to increasing of the contact angle and allows us to obtain superhydrophobic coatings. We have shown that the wettability properties can be regulated by deposition parameters. Experimentally determined optimal values of deposition parameters ensure uniform deposition of the film with superhydrophobic properties.

We present the results of studying the structure of gold nanoparticles synthesized on the silicon surface by two techniques: pulsed laser ablation and magnetron sputtering. The surface morphology is examined by scanning electron microscopy. The structure of the obtained gold nanoparticles is analyzed by transmission electron microscopy and electron diffraction. It is shown that nanoparticle sizes and crystal structures can be controlled by their thermal annealing. Mechanisms occurring during annealing of thin gold films and also their effect on the formation of nanoparticles with different structures are investigated.

Tin with its low melting point and vapor pressure is a good model material to investigate laser ablation mechanisms under various ambient conditions. Here we measured the nanosecond-laser-induced damage thresholds of tin in vacuum, air, and water. The threshold fluence is found to be ~ 0.1 J/cm2 regardless of the environment unlike more refractory metals when threshold values in water are considerably higher than those in air. Analysis of the morphology and chemical composition of the irradiated surface as well as numerical simulations of tin laser heating demonstrate that the observed surface modification is due to melting but not oxidation. For the case of water environment, the conductive heat transfer to water is found to play only a minor role in tin heating and melting. The simulations show also that the formation of a water vapor layer near the tin surface occurs at a considerably higher fluence, above 0.15 J/cm2, and thus the surface damage is not affected by scattering of the incident laser light by the vapor–liquid interface, typical for more refractory metals. Peculiarities of laser ablation of low-melt materials in liquids and nanoparticle formation are discussed.

The nanosecond-laser-induced damage thresholds of gold, silver and gold-silver alloys of various compositions in air and water have been measured for single-shot irradiation conditions. The experimental results are analyzed theoretically by solving the heat flow equation for the samples irradiated in air and in water taking into account vapor nucleation at the solid-water interface. The damage thresholds of Au-Ag alloys are systematically lower than those for pure metals, both in air and water that is explained by lower thermal conductivities of the alloys. The thresholds measured in air agree well with the calculated melting thresholds for all samples. The damage thresholds in water are found to be considerably higher, by a factor of ∼1.5, than the corresponding thresholds in air. This cannot be explained, in the framework of the used model, neither by the conductive heat transfer to water nor by the vapor pressure effect. Possible reasons for the high damage thresholds in water such as scattering of the incident laser light by the vapor-liquid interface and the critical opalescence in the superheated water are suggested. Optical pump-probe measurements have been performed to study the reflectance dynamics of the surface irradiated in air and water. Comparison of the transient reflectance signal with the calculated nucleation dynamics provides evidence that the both suggested scattering mechanisms are likely to occur during metal ablation in water.

Degradation-resistant two-dimensional metal–fluoropolymer composites consisting of gold nanoparticles coated with a thin fluoropolymer film were deposited on a substrate by hot wire chemical vapour deposition (HWCVD) and ion sputtering. The morphology and optical properties of the obtained coatings were determined. The thickness of the thin fluoropolymer film was found to influence the position of the surface plasmon resonance peak. Numerical calculations of the optical properties of the deposited materials were performed using Mie theory and the finite-difference time-domain (FDTD) method. The calculation results are consistent with the experimental data. The study shows that the position of the resonance peak can be controlled by changing the surface concentration of particles and the thickness of the fluoropolymer coating. The protective coating was found to prevent the plasmonic properties of the nanoparticles from changing for several months.

The dynamics of heating and vaporization of gold in vacuum under the action of laser pulses of low intensity, when the main ablation products are neutral particles, is investigated by mass spectrometry and numerical modeling. The laser-ablation plume is found to consist of gold atoms and dimers with kinetic energies considerably higher than their thermal energy upon evaporation. Nanostructured gold films are synthesized by depositing the ablation products onto a substrate. Formation mechanisms of the gold nanostructures and possibilities of controlling their sizes are discussed.

This paper describes the method of obtaining composite coatings consisting of silver nanoparticles covered by a fluoropolymer film. The morphology and optical properties of resulting coatings are given within. The presence of a surface plasmon resonance (SPR) minimum of silver nanoparticles deposited on glass and fused silica surfaces has been revealed. The paper describes a shift towards the infrared (IR) region when the average size of deposited silver nanoparticles is changed. However, coating the nanoparticles in a fluoropolymer film does not significantly shift their resonance.

The mass thickness of thin metal films is an important parameter determining the film structure, however a robust routine method for its determination is still missing. In this work, we have developed a simple optical method for determining the mass thickness of gold films with arbitrary morphology on transparent substrates in the range 1–20 nm. The method is based on film spectrophotometry in the far-UV range when the light attenuation is due to interaction with core electrons and thus the influence of the film morphology is negligible. The calibration was performed at a wavelength of 200 nm for gold films of known thickness and a good agreement with the Beer–Lambert law was obtained. The feasibility of the method was demonstrated with gold films of various morphologies produced on quartz substrates by pulsed laser deposition.

The evolution of the morphology and composition of the single-crystal silicon surface irradiated by infrared and visible nanosecond laser pulses is investigated as a function of processing parameters (laser fluence, irradiation spot size, the number of pulses, background gas pressure and composition). Two types of periodic surface microstructures are obtained with IR (1064 nm) laser pulses in a narrow fluence range of 3–6 J/cm2. At a relatively low number of laser pulses applied, a grid of cleavage cracks is produced within the irradiation spot along the crystal orientation. With further Si irradiation, periodic microhillocks are formed in the nodes of the crack grid. Silicon surface with such microhillocks exhibits superhydrophilic properties which are retained during prolonged storage in air. The cracks are produced in any environment (including vacuum) but the microhillocks are observed only in the presence of oxygen. No periodic structures were observed with visible (532 nm) laser pulses. Mechanisms of nanosecond laser-induced periodic microstructure formation on silicon are discussed.

We have analysed changes in the oxidation state of SiOx films produced by pulsed laser deposition in a background gas with different partial pressures of oxygen. The optical properties of the films in IR range are shown to be close to those of SiO2 while the total oxidation degree is considerably less than 2. It is suggested that the film consists of oxidized and unoxidized regions due to preferential oxidation of the periphery of the silicon ablation plume during expansion. These regions are overlapping in the film if the laser beam is scanned on the target.

Pulsed Laser Ablation in Liquid (PLAL) is a flexible technique for synthesis of nanoparticles of various materials, in particular of noble metals [1]. Despite of the widespread use of this method, processes involved in PLAL are still poorly understood. The presence of the liquid makes the PLAL process much more complicated as compared to conventional ablation in vacuum or in an ambient gas. The poor current knowledge of the PLAL process can be illustrated by the example of the laser-induced damage thresholds (DTs) in liquid. The available data on the DTs under PLAL are rather contradictory and provide threshold laser fluences higher [2, 3], equal to [4], and lower [5] than the corresponding values in air. Various mechanisms are invoked to explain the differences. Thus, higher DTs under PLAL, observed in most experiments, are explained by conductive heat transfer to the liquid [3] or by vapor pressure and confinement effects [2] while an increase of the surface absorptivity in liquid or enhanced shockwave recoil pressure are assumed to be responsible for lower thresholds [5].

The optical properties of nanocomposite material consisting of gold nanoparticles without/with silicon suboxide thin film were obtained. The gold film was deposited by thermal vacuum evaporation and then it was annealed in a vacuum chamber to form gold nanoparticles. The silicon suboxide thin films were deposited by the gas-jet electron beam plasma chemical vapor deposition method. The intensity of the localized surface plasmon resonance increased and the plasmon maximum peak shifted from 520 nm to 537 nm.