On the Use of SNMS for the Manufacture Control of Ag Colloid Containing Sol-Gel Films on Glass

摘要

The colour of glass can be controlled either by the composition of the bulk material or by appropriate surface coatings. The present studies deal with thin SiO_2-like films (0.5 - 1 μm) on soda lime and fused silica glass substrates containing nanometer-sized Ag colloids fabricated by a sol-gel process The formation of the Ag-colloids and the densification of the films can be controlled by a heat treatment at different temperatures. UV-VIS investigations show that this heat treatment leads to a reduction of the amount of Ag-colloids in the films and therefore to a bleaching of the films This effect can be attributed either to an oxidation of the silver particles or to a diffusion of Ag from the film into the substrate. To distinguish between these two possibilities, the influence of the annealing temperature on the elemental distributions in the sol-gel films deposited on different glass-substrates has been investigated with the high frequency mode HFM of secondary neutral mass spectrometry SNMS, complementary to measurements with optical spectroscopy and electron microscopy. For Na-free glass substrates the SNMS concentration depth profiles reveal the presence of Ag in the films even at high temperatures, while a diffusion transport of Ag into the substrate for soda lime glass is found. With increasing baking temperature the Ag content in the film is continuously reduced, and falls finally beyond the detection limit at 600°C On the other hand, Ag is not detected in the substrate and is also not expected to evaporate at such a low temperature. Hence, we conclude that Ag enters the glass and spreads there with high mobility.