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Laser-based techniques are used more and more frequently for the cleaning of artifacts. Due to the different behavior of each material, when it is irradiated, studies and experiments are performed in order to find the optimum laser parameters for each case. In this work, the laser cleaning of coins is examined. Coins are studied with analytical methods in order to detect the corrosion products and the accretions. This information along with the composition of the coins’ alloys is fed into an in-house developed program which estimates the penetration depth of the laser beam as well as the laser fluence for which the alloy starts to melt. Exploiting this information, laser cleaning of coins is performed with various conditions and parameters. Finally, the result is evaluated by using microscopic methods. From this research, it was found that the laser cleaning of copper, silver and aluminum alloys is feasible with Q-switched Nd:YAG at 1064 nm. Also, higher level of corrosion and accretions requires higher laser intensity. For low corrosion level on copper alloys, a thin water film on the irradiated area is beneficial.

Abstract: Microcrystalline indium oxide (InOx) films with thickness of 120–1600 nm were prepared by dc reactive magnetron sputtering in various mixtures of oxygen in argon at room temperature. The depositions were carried out onto Corning 7059 glass and silicon substrates. The conductivity of the as-deposited films can change in a controllable and fully reversible manner by about six orders of magnitude by alternately exposing the films to ultraviolet (UV) light (hv≥3.5eV) in vacuum and reoxidizing them in ozone. The microstructure of the films was investigated using transmission electron microscopy (TEM) and electron diffraction. For this purpose, films with a thickness of about 100 nm were deposited onto NaCl substrates. The surface and depth composition of the films were examined using Auger electron spectroscopy (AES) combined with depth profiling analysis. The depth profiles showed that all the films exhibit an extremely good in-depth uniformity, all the way to the interface with the glass substrate, regardless of their thickness. Quantitative Auger and energy dispersive x-ray (EDX) analyses were employed to determine the stoichiometry of the films. An oxygen deficiency of 2–5% has been observed with respect to the stoichiometric composition. The effects of film thickness and oxygen content in the sputtering gas on the stoichiometry were examined. Both AES and EDX analyses confirmed that the stoichiometry is invariant for these parameters.

Given paper presents the results of industrial waste recycling - steel cooling refuse, etching refuse and alumina containing waste. In order to characterize the microstructure and chemical composition of a glass-ceramic material obtained from Latvian industrial waste, the scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy and X-ray diffraction (XRD) analyses were used. In the glass-ceramic material various crystalline phases such as quartz, hematite, anorthite, spinels etc. were identified. The crystalline phases contain a higher amount of metallic elements (e.g. Al, Cr, Fe, Ni and Zn and most probably also other heavy metals) than the residual glassy phase. Relations between microstructure, chemical composition and mechanical properties were established.