KSbOSiO 4 microcrystallites as a source of corrosion of blue-green lead-potassium glass beads of the 19th century Presently, deterioration of glass beads is a significant problem in conservation and restoration of beaded exhibits in museums. Glass corrosion affects nearly all kinds of beads but cloudy blue-green ones are more than others subjected to disastrous destruction. However, physical and chemical mechanisms of this phenomenon have not been understood thus far. This article presents results of a study of elemental and phase composition of glass of the blue-green beads of the 19th century obtained from exhibits kept in Russian museums. Using scanning electron microscopy, X-ray microanalysis and X-ray powder analysis we have detected and investigated Sb-rich microinclusions in the glass matrix of these beads and found them to be micro crystallites of KSbSiO 5 . These crystallites were not detected in other kinds of beads which are much less subjected to corrosion than the blue-green ones and deteriorate in a different way. We believe that individual precipitates of KSbSiO 5 and especially their clusters play a major role in the blue-green bead deterioration giving rise to slow internal corrosion of the bead glass.

Sodium peroxostannate nanoparticles with graded composition were produced from aqueous hydrogen peroxide-sodium hydroxostannate solution. The uniform particles were converted to composition graded sodium stannate by mild thermal treatment for peroxide decomposition and yielded yolk-shell tin dioxide particles by dilute acid treatment. The mechanism of formation of the graded sodium concentration is explained in view of the solubility of peroxostannate in HO-HO solution and based on Sn NMR, XRD, dynamic light scattering (DLS) and electron microscopy studies. Initial studies illuminating sensitive hydrogen sensing by yolk-shell tin oxide particles are presented.

In this article is a report of SnO2 deposition by aerosol‐assisted (AA)CVD from tin complexes, [Sn(18‐Cr‐6)Cl4] and [Sn(H2O)2Cl4](18‐Cr‐6). The structure and properties of the precursors, used to synthesize SnO2 layers by AACVD for the first time, are characterized with the help of X‐ray diffraction (XRD), infrared (IR), and thermogravimetric analysis (TGA). Each complex is deposited by AACVD at 250, 400, and 500 °C in a flow of N2. The resulting films are studied by XRD and atomic force microscopy (AFM). Gas‐sensing properties of the deposited layers are tested to 10 ppm NO2 in air. The maximum sensor response to the analyte is measured at 300 °C.

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