Surface protection of fluoroindate glasses by sol-gel dip-coated SnO2 thinlayers

SnO2 coatings were deposited by a sol-gel dip-coating process to shield flu oroindate glasses (40In-F-3:16BaF(2):20SrF(2):20ZnF(2):2NaF:2GaF(3)) agains t corrosion in aqueous environments. The effect of the number of coating ap plications and of the withdrawal speed on the thickness, density and roughn ess of tin oxide films was investigated by X-ray reflectivity. Film thickne ss increases both with the number of coating applications and the withdrawa l speed. The aqueous leaching of uncoated and SnO2-coated fluoroindate glas ses was studied by scanning electron microscopy (SEM) and infrared spectros copy (FTIR), showing that the glass surface was protected against hydrolyti c attack. (C) 1999 Elsevier Science B.V. All rights reserved.