Initial corrosion stages of a heavy metal fluoride glass in water

A 50ZrF(4)-33BaF(2)-10YF(3)-7AlF(3) (mol%) pre-sputtered glass was corroded in H2O for durations between 1 and 50 min at 20 degrees C, 40 degrees C, 60 degrees C and 80 degrees C. The profiles of Zr, Ba, Y and Al were measured by secondary neutral mass spectrometry, H was measured by nuclear reaction analysis, whereas O was monitored using Rutherford backscattering spectrometry. On the basis of these results it is shown that the corrosion zone approaches a composition near that of the BaZrF6 phase. Further, a modified corrosion model for the initial stages of the glass attack is proposed, where H2O is the initiating species. (C) 1999 Elsevier Science B.V. All rights reserved.