Evidence from infrared spectroscopy of structural relaxation during field assisted and chemically driven ion exchange in soda-lime-silica glasses

M. D. Ingram, M.-H. Wu, A. Coats, E. I. Kamitsos, C. -P. E. Varsamis, N. Garcia, M. Sola

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Evidence is provided by infrared reflectance spectroscopy of structural relaxation occurring in ion exchanged surface layers in commercial soda-lime-silica glasses. Monovalent cations (K+, Ag+ and Li+) are introduced from molten nitrate baths both by simple diffusion and with the assistance of externally applied electric fields. In the case of K+ ions, a highly resistive layer is created and is characterised by impedance spectroscopy. The mid infrared spectra provide information on changes in the silicate network: they show that the introduction of Li+ and Ag+ leads to a disproportionation reaction with conversion of Q(3) into Q(2) and Q(4) species. In contrast, the introduction of K+ ions leads to the opposite (i.e. comproportionation) reaction, where Q(2) and Q(4) are converted into Q(3) units. These processes are chemically driven; they are impeded, e.g. by the build up of internal pressures accompanying the introduction of the larger K+ ion. The results provide direct evidence for cation-induced relaxations in the glass network (CAIRON).

Original languageEnglish
Pages (from-to)84-89
Number of pages6
JournalPhysics and Chemistry of Glasses
Volume46
Issue number2
Publication statusPublished - Apr 2005

Cite this