Surface Studies Of Borate Glasses

X-ray photoelectron spectroscopy and low-energy ion scattering spectroscopy have been used to characterize the surfaces of boron oxide, sodium borate and barium aluminoborate glasses. It is shown that the Bls binding energy cannot distinguish between 3-fold and 4-fold coordinated boron. The ISS analyses show a depletion of modifier-ions in the surface monolayer of the glasses. In the case of melt surfaces, this modification of the surface can be attributed to evaporation and diffusion. In the case of fracture surfaces, it is necessary to consider the effects of ionic fractoemission and surface reconstruction.