BULK AND SURFACE CRYSTALLIZATION OF POTASSIUM HEPTAGERMANATE GLASS

Authors
LAUDISIO G CATAURO M
Citation
G. Laudisio et M. Catauro, BULK AND SURFACE CRYSTALLIZATION OF POTASSIUM HEPTAGERMANATE GLASS, Physics and Chemistry of Glasses, 38(5), 1997, pp. 244-245
Citations number
8
Categorie Soggetti
Material Science, Ceramics","Chemistry Physical
Journal title
Physics and Chemistry of Glasses → ACNP
ISSN journal
00319090
Volume
38
Issue
5
Year of publication
1997
Pages
244 - 245
Database
ISI
SICI code
0031-9090(1997)38:5<244:BASCOP>2.0.ZU;2-#
Abstract
The devitrification behaviour of K(2)0.7GeO(2) glass examined by diffe rential thermal analysis and x-ray diffraction is reported. The effect of the specific surface area of the glass samples on the crystallisat ion mechanism has been pointed out. Powdered samples were found to dev itrify in two steps: in the primary transformation unidentified metast able crystals are formed and in the second they are converted into sta ble K2Ge7O15 crystals. Bulk samples devitrify in a single step into K2 Ge7O15 crystals. The activation energy for crystal growth in bulk samp les is 268 kJ/mol.