Vidros Ceramicos Nanocristalinos Transparentes

glass ceramics containing nanocrystalline phases that present non-linear optical properties, namely second harmonic generation (shg), have potential application in photonics, namely in all-optical and electro-optical systems. the goal of this work was the preparation and characterization of glass samples in the system geo2？sio2？nb2o5？k2o, as well as the production of transparent, nanocrystalline glass ceramics. the glass samples were prepared and characterized by density, dta and raman spectroscopy measurements. an increase in density and a decrease in tg and tx-tg were observed with increasing amount of geo2. heat treatments were performed and the crystalline phases k3.8nb5ge3o20.4 and k3nb3si2o13 were identified and related with the first exothermic peak of the dta analysis. a germanosilicate composition with 50 mol% of glass former showed good ability to undergo bulk crystallization. in fact, a transparent glass ceramic containing crystal sizes of ~20-25 nm, was obtained.