Synthesis of transparent conductive coatings is a promising direction of modern nanotechnological research.
Thin nanostructured noble-metallic films demonstrate nonlinear optical effects in visible spectral range because of their
plasmonic properties [1]. In addition, optical characteristics of these thin films strongly depend on the period of the
formed surface structures [2]. If the distance between deposited particles almost equals their sizes, the optical properties
of the randomly deposited structures may considerably differ from these for periodical structures [3].
In this work, we have studied the degree of the morphology influence (particle diameter in the colloid, the
distance between the deposited particles, the number of layers etc.) on the optical and electrical properties of the
deposited thin film of bimetallic gold and silver clusters. In this work we used CW-laser with moderate intensity in liquid
(water or ethanol) for synthesis nanoparticles of noble metals. For the formation of quasi-periodically arranged clusters,
particle deposition from the colloidal systems is used. The optical properties of the deposited bimetallic films are shown
to change as a function of composition and geometry in agreement with the modeling of the optical properties.
Synthesis of nanotructured metal-carbon materials by laser irradiation is an actual branch of laser physics and
nanotechnology. Laser sources with different pulse duration allow changing the heating rate with realization of different
transition scenarios and synthesis materials with various physical properties.
We study the process of the formation of nanostructured metal-clusters and complexes using laser irradiation of
colloidal systems which were consisted of carbon micro- nanoparticles and nanoparticles of noble metals.
For carbon nanoparticles synthesis we use the method of laser ablation in liquid. For the realization of different
regimes of laser surface modification of the target (glassycarbon and shungite) and the formation of micro- nanoparticles
in a liquid the YAG:Nd laser with a pulse duration from 0.5 ms up to 20 ms (pulse energy up to 50J) was applied.
We have used the CW-laser with moderate intensity in liquid (water or ethanol) for nanoparticle of noble metals
synthesis. Thus, colloidal systems were obtained by using CW-laser with λ = 1.06 μm, I ~ 105-6 W/cm2, and t = 10 min.
The average size of resulting particles was approximately about 10 to 100 nm. The nanoparticle obtaining was provided
in the colloidal solution with different laser parameters.
In this work we have investigated the mechanism of the metal-carbon cluster formation during the process of
irradiation of colloidal system which were consisted of separate carbon, silver and gold nanoparticles. This system was
irradiated by nanosecond laser (100 ns) with average power up to 50W.
Gold nanoparticles (Au NPs) attract particular attention because of their unique size-dependent chemical, physicochemical and optical properties and, hence, their potential applications in catalysis, nanoelectronics, photovoltaics and medicine. In particular, laser-produced colloidal nanoparticles are not only biocompatible, but also reveal unique chemical properties. Different laser systems can be used for synthesis of these colloids, varying from continuous wave (CW) to ultra-short femtosecond lasers. The choice of an optimum laser system is still a challenge in application development. To bring more light at this issue, we investigate an influence of laser parameters on nanoparticle formation from a gold target immersed in deionized water. First, an optical diagnostics of laser-induced hydrodynamic processes taking place near the gold surface is performed. Then, gold nanoparticle colloids with average particle sizes smaller than 10 nm and a very narrow dispersion are shown to be formed by CW laser ablation. The obtained results are compared with the ones obtained by using the second harmonics and with previous results obtained by using femtosecond laser systems.
For obtain nanostructured surfaces on various materials the method of laser deposition of metals from solutions (LDMS)
was used. As a solution were used nanosystems: oxide copper (CuO) and a two-component solution of nickel (Ni) and
carbon nanotubes. Deposition occurred action of pulse-periodic laser radiation (a wave length 1.06 microns, a pulse
length 100ns, a repetition rate of impulses 20 kHz) various power. Laser radiation was focalized on a substrate from a
quartz glass and copper. Obtain samples were research on a raster-type electronic microscope (Quanta 200/3D) and an
atomic-force microscope (Ntegra Aura). As a result deposition occurred only on a trajectory of a motion of a beam.
Deposition layers has good adhesion to a substrate surface. <<The soft mode>> actions of laser radiation as the substrate
surface is not exposed to thermal action. The layer roughness made 270nm at height of a relief about 2 microns. The
offered method of deposition of metals from the colloid solutions by means of laser radiation is simple, inexpensive, and
to substrates scaled to the big areas and length of the precipitated layer.
Diagnostics of laser-induced instabilities on surface of substance has been carried out by means of fractal geometry and nonlinear dynamics methods. The spatial and temporal characteristics of optical images of melted metal surface were obtained. The obtained characteristics may be used for automatic control by laser technological processes. (Summary only available)
For the diagnostics of processes induced by laser radiation we developed the system on basis of copper laser. This system (laser monitor) consists of laser brightness amplifier, CCD-camera, computer, and allows to obtain the image of a processing surface through plasma plume in a real time. In contradistinction to classical schemes of laser processing our system realizes continuous visual control of processing surface directly in the process of laser radiation interaction with material. The computer analysis of obtained information allows to form control signals for the laser technological complex. The offered system provides the increasing of reliability and accuracy of carrying out measurements and can be used in various technological processes of treatment of metal. In this report we present the result of processing the optical images of dynamic processes on substance surface by fractal geometry methods.
The experimental studying of laser-induced hydrodynamic phenomena has been carried out by the system on base of laser brightness amplifier. The surface waves were registered and their parameters were determined. The form of free surface of melted by the laser radiation material was determined. New results of the field to study the laser- induced dynamic processes on the substance surface by the fractal geometry approach are presented.
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