Laser-Induced Nanocluster Thin-Film Systems with Controlled Topology and Composition: The Possibility of Creating Superconducting Structures Based on New Physical Principles

Crystallography Reports - The physical properties of solid structures depending on the boundary conditions in topologically ordered nanocluster systems are discussed. These systems are synthesized...     

Laser-induced synthesis of metal–carbon materials for implementing surface-enhanced Raman scattering

Metal–carbon materials exhibiting surface-enhanced Raman scattering have been synthesized by laser irradiation of colloidal systems consisting of carbon and noble metal nanoparticles. The dependence of the Raman scattering intensity on the material composition and laser irradiation conditions has been investigated. The possibility of recording the Raman spectrum of organic dye rhodamine 6G, deposited in amount of 10^–6 M on the substrate obtained from a colloidal solution is demonstrated.     

Optical properties of multilayer bimetallic films obtained by laser deposition of colloidal particles

The optical properties of multilayer bimetallic films composed of silver and gold nanoparticles have been investigated. The dependence of the transmission spectra of the films on their morphology is demonstrated. A finite-difference time-domain (FDTD) simulation has confirmed that there is a dependence of the transmission spectra on the average distance between particles and the number of deposited layers.     

Measurements of electrophysical properties of metal microcontacts using fractal geometry methods for the analysis of atomic-force-microscopy data

A new approach to analyzing the conductivity of metal microcontacts of the fractal type is proposed. It is shown that the resistance of such a microcontact depends strongly on its morphology (total characteristic including the size, shape, and spatial organization, which are determined by atomic force microscopy). A method for calculating the resistance of a microcontact by measuring its height map is proposed.     

Pulse laser deposition of cluster nanostructures from colloidal single-component systems

We study the formation and deposition of clusters of nanoparticles from colloidal systems onto a support surface as a result of local pulse laser impact. The processes of abnormal diffusion influencing the formation of relief due to changes in the diffusion coefficient near surface irregularities are analyzed. Numerical simulation is performed for the mechanism of deposition of particles from the colloidal system as a result of local laser impact.     

Melting of carbon heated by focused laser radiation in air at atmospheric pressure and temperature below 4000 K

The melting of carbon at a pressure of about 1 atm is observed. The escape of liquid carbon from the heating region and its spread over the sample surface are observed in the experiments. The structural changes in graphite occurring in the melting region are determined from scanning tunneling microscope (STM) images obtained by means of an atomic force microscope and from Raman spectra. The STM images exhibit significant rearrangement of the structure of the graphite surface in the region of the escape of liquid carbon. The Raman spectra show that the graphite ordering degree increases significantly.