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Electric spike emission was observed for the first time for thin polymer foils irradiated with low energy light ion microbeams at overlapping fluences, when placing them in between two vessels filled with etchant and distilled water, respectively, and applying a low sinusoidal transverse voltage. The various shapes of recorded spike types are described and examined. From their emergence that occurs after different derived etching times, and the inter-correlation of different spike parameters, we draw the first conclusions about their formation mechanism, behavior, and usefulness for technical applications. [ABSTRACT FROM AUTHOR]

A number of sophisticated methods are related to the technology of thin-film complex materials. One of them, although less used, is the sputtering of targets with low-energy ions. Using this method, various thin multi-element composites can be formed either as amorphous mixtures or crystalline structures (e.g. MAX phases), or something in between. In this work, 25 keV Ar+ ion sputtering was used to synthesize thin ternary systems based on Zr, In, and C with a stoichiometric ratio of ∼2:1:1. The prepared samples were exposed to 2 MeV W+ ion irradiation (for comparison, 1/3 of each sample remained pristine) to determine their response to heavy ion bombardment. The analysis was focused mainly on the surface morphology. It has been shown that using ion sputtering, thin ternary composites with a very smooth surface and homogeneously distributed phases can be prepared. After ion bombardment, well distinct self-organized structures appeared – parallel nanostripes growing in several directions on both irradiated and unirradiated regions of the composites. As a driving force of the patterns, an immiscibility of the building elements In and C was proposed. The process of the self-assembly consists in the coordinated expansion of the phase separation that occurs at elevated temperatures induced by ion irradiation. The results indicate that using ion beam sputtering with subsequent MeV ion bombardment, multi-element thin-film composites exhibiting self-organized morphology can be synthesized. [ABSTRACT FROM AUTHOR]

The synthesis of metallic nanoparticles has raised a growing interest in recent years, owing to the potential applications as biosensors or contrast medium for X-ray diagnostic imaging. The gold nanoparticles have been created by laser ablation in distilled water assisted by an electric field. The different sizes and shapes of generated nanoparticles have been morphologically characterized by Scanning Electron and Atomic Force microscopies. The optical properties of the suspensions containing nanoparticles have been studied with the UV–VIS spectroscopy. The nanoparticle dispersion, as well as their composition and concentration, have been analyzed by Energy Dispersive X-ray analysis. [ABSTRACT FROM AUTHOR]

Thin films consisting of 17 groups of Hf/In/C multilayers cyclically alternating layers of Hf, In and C each with a thickness of 4–5 nm were synthesized by ion sputtering using a 25 keV Ar+ ion beam with 400 µA current and targets made of pure hafnium, indium and carbon. The films were subsequently annealed in vacuum at 120°C for 24 hours to induce intermixing of elements phases, their interaction, and formation of the Hf-In-C nanostructures (including the Hf2InC MAX phase). After fabrication, a part of the pristine (as deposited) samples was irradiated by 200 keV Ar+ ions at high fluences 1015 and 1017 cm−2. Both samples (as prepared and irradiated) were analyzed by IBA nuclear analytical methods, as well as by AFM and TEM microscopic techniques, and by XPS and profilometry to understand the microstructural evolution. Moreover, nanoindentation analysis was performed to assess the effects of ion irradiation on the microstructure and mechanical properties of the films. The experimental results showed that thin Hf-In-C nanostructured films can be formed by ion sputtering with promising mechanical parameters. The irradiated Hf-In-C films were found to be resistant only up to a fluence of about 1015 Ar cm−2. At higher fluences it degrades, and Hf2InC transforms to the binary HfC0.95 phase due to sublimation of In. At 1017 cm−2 the original matrix (including M2AX) is destroyed, and instead, a mixture of MX binary phases (e.g. HfC0.95) and crystalline oxides (e.g. HfO2 and In2O3) are formed. [ABSTRACT FROM AUTHOR]

A diffusion calculation was performed to simulate the migration kinetics of both analytes and enzymatic reaction products in enzyme-clad nanopores of different sizes and shapes, to estimate the limits of detection, response time and cleaning time of such biosensors, via the maximum possible reaction product enrichment in such pores and the time required for saturation of the corresponding concentration distributions. From this, conclusions concerning the optimum biosensor dimensions are derived. [ABSTRACT FROM AUTHOR]