We describe a new approach to the fabrication of surface-enhanced Raman scattering (SERS) substrates using gold nanorod (GNR) nanopowders to prepare concentrated GNR sols, followed by their deposition on an opal-like photonic crystal (OPC) film formed on a silicon wafer. For comparative experiments, we also prepared GNR assemblies on plain silicon wafers. GNR-OPC substrates combine the increased specific surface, owing to the multilayer silicon nanosphere structure, and various spatial GNR configurations, including those with possible plasmonic hot spots. We demonstrate here the existence of the optimal OPC thickness and GNR deposition density for the maximal SERS effect. All other things being equal, the analytical integral SERS enhancement of the GNR-OPC substrates is higher than that of the thick, randomly oriented GNR assemblies on plain silicon wafers. Several ways to further optimize the strategy suggested are discussed.

No abstract

The experimental investigations of the interaction of the pulsed laser radiation with different types of thin films are presented. Polycluster diamond films, aluminum nitride films, and indium tin oxide films were investigated. A high efficiency inelastic scattering of light due to optoacoustic interaction was registered. The spectral features of the scattered light are defined by the morphology of the samples.

An ac magnetization technique was used to study superconductivity in tin loaded nanoporous silica matrices, opal matrix and two porous glasses. The behavior of type-II superconductors with a sharp transition at zero bias field was observed. Regular increase in the superconducting temperature up to 4.2 K and in a critical field up to H c2 (0) ∼ = 54 kOe with decreasing pore size was found. A crossover from the upturn to the common downturn curvature in the H c2 (T) line was seen for all nanocomposites; the upturn curvature was more pronounced for the matrix with the finest pores.

No abstract