Diffusion of Ag species into the surface layers of the MgO–Al2O3–TiO2–SiO2 glass stimulates the crystallization
processes therein during subsequent thermal treatment. It was found that the silver doping significantly increases
the microhardness of glass and glass ceramics. The effect of the Ag diffusion and the subsequent hightemperature treatment (T > Tg) on the structure and luminescence properties of the MgO–Al2O3–TiO2–SiO2
glass was studied. The thermal evolution, structure and properties of the glass and glass ceramics were investigated by the DSC method, XRD analysis and luminescence spectroscopy. It was found that the Ag diffusion into
the surface layers leads to the formation of numerous different luminescent molecular Agn clusters. The MgO–Al2O3–TiO2–SiO2 glass and glass ceramics subjected to the Ag diffusion can operate as effective down-converters
of the radiation demonstrating the effective transformation of UV and blue light into the radiation of red and NIR
spectral range.