PHOTOLUMINESCENCE OF A SODA LIME GLASS EXCHANGED WITH SILVER IONS

A commercial soda-lime glass subjected to ion exchange with Ag+ at dif ferent temperatures and times is studied by photoluminescence (PL), op tical absorption (OA) and transmission electron microscopy (TEM). Some samples were reheated in air and in a reducing atmosphere (N-2-H-2) t o favour the reduction of the Ag+ ions. The evolution of the silver co lloids with the exchange parameters is monitored by means of the carac teristic absorption band at 420 nm. PL spectra reveal that the samples exchanged with silver show a broad emission band centered around 600 nm upon excitation in the nearby ultraviolet, which intensity is very sensitive to temperature and exchange time. The excitation spectra exh ibit a broad band with three peaks at about 360, 395 and 445 nm relate d to different types of silver centres.