Surface crystallization of β-BaB2O4phase using a CO2 laser source

This letter describes decrystallization process of the beta-BaB2O4 phase on the surface of 63BaO-26B(2)O(3)-11TiO(2) glassy sample when irradiated by a CO2 laser beam for 30-40 s, using a laser power of approximate to 1.7 W. An analysis by optical microscopy of the irradiated region showed that the glass surface contained crystallites with the same morphology as those observed after traditional crystallization in an electric furnace. However, the crystal growth rate and the crystallite sizes appeared to be higher than those obtained by heating in an electric furnace. X-ray diffraction of the irradiated region showed a preferential orientation of the beta-BaB2O4 crystallites on the glass surface. (C) 2002 Elsevier Science B.V. All rights reserved.