STUDY OF DIFFUSION IN GLASS*

An introductory study was made of diffusion into glass from salts, with silver nitrate as the chief source of diffusing particles. The optimum test conditions were a temperature of 900°C. and a test time of 108 hours. The results noted were (1) effect of time, (2) effect of temperature on the distance of diffusion, (3) variation of silver concentrations in the glass with the distance of diffusion, and (4) a check of Fick's law of diffusion. The concentration gradient of silver from a diffusing interface was determined with the use of a spectrograph and corresponding particle sizes with an ultramicroscope. In addition to the silver nitrate, a number of other salts were tested at several temperatures. The development of Liesegang rings was noted in some of the samples. The nature of diffusion in glass was deduced from the results.