FACTORS AFFECTING EXTENDED HYDRATION DEPTHS IN ION-IMPLANTED FUSED-SILICA

The implantation of fused silica to high collisional energy deposition levels allows penetration of hydrogenic species, either from aqueous solutions or atmospheric ambients, to depths exceeding the theoretical ranges by a factor of 2-3. In the case of ambient exposure, hydration is known to persist over periods of years after implantation, Extende d depths are also seen for etching, gaseous implant distribution, and alkali depletion. The phenomena are examined using the modeling of str ained silica structures as the driving force for slow fracture and the extensive structural understanding provided by sol-gel investigations .