An investigation of the finite depth square well model is presented in this article: model features and limitations, concerning size dependent band gap of semiconductor quantum structures, are presented and discussed. Model predictions are compared with large sets of experimental data for III-V, II-VI and lead salt semiconductor quantum dots and quantum wires. Matrix influence on the confinement is studied by modeling experimental results for colloidal CdS, CdSe, CdTe and InP quantum dots. The effect of quantum structure dimensionality is investigated and successfully simulated for colloidal CdSe and InP experimental data and Si first-principle calculations. Finally, model limitations for narrow band gap semiconductors are studied and discussed

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Following the recent finding that luster decorations in glazes of historical pottery consist of copper and silver nanoparticles dispersed in a glassy medium, the glaze in-depth composition and distribution of copper nanoparticles, copper ions, and their local environment have been studied in original samples of gold and red luster. The study has been fully carried out by nondestructive techniques such as Rutherford backscattering spectrometry, ultraviolet and visible spectroscopy, x-ray fluorescence, and extended x-ray absorption fine structure (EXAFS). Elemental analyses indicate that gold decorations are characterized by silver and copper, while red decorations by copper only. The color is determined mainly by metal nanoparticles. Specifically, silver nanoparticles determine the gold color, while the red color is determined by nanoparticles of copper. EXAFS measurements, carried out at the Cu K edge, indicate that in both gold and red luster copper is mostly the oxidized form (Cu+ and Cu2+) with a large prevalence of Cu+. States and local environment of copper ions are similar to those found in copper–alkali ion-exchanged silicate glass samples. This strongly supports the view that luster formation is mediated by a copper– and silver–alkali ion exchange as a first step, followed by nucleation and growth of metal nanoparticles.

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The clustering process of gold atoms in ion-implanted silica, during annealing in different atmospheres, is experimentally investigated and phenomenologically described. With respect to inert (Ar) or reducing (H2-Ar) atmosphere, annealing in oxidizing (air) atmosphere is the most effective in promoting cluster formation above 700–800°C due to a thermally activated correlated diffusion of gold atoms and excess oxygen molecules coming from the atmosphere

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