First stages of crystalzation in a silicate glass: Study by high-resolution electron microscopy

✍ Scribed by Ramos, Aline ;Gandais, Madeleine

• Publisher: Wiley (John Wiley & Sons)
• Year: 1989
• Tongue: English
• Weight: 576 KB
• Volume: 11
• Category: Article
• ISSN: 0741-0581
• DOI: 10.1002/jemt.1060110310

✦ Synopsis

The first stages of crystallization have been investigated for a glass in the system Si02-A1203-Li20 with small amounts of titanium and zirconium as nucleating elements. The studies were performed by electron diffraction and electron microscopy in high-resolution mode. It has been found that the two phases forming the final glass ceramic crystallize successively. The first one gives small crystallites ( 4 nm) randomly dispersed. The lattice plane images in several orientations are in good agreement with TiZr04 crystal lattice. At 780°C the average crystal size increases with increasing time of the heat treatments from 2.5 nm at 0.5 h to 4.5 nm at 2 h and then remains nearly constant. The crystallization of the second phase, a silicate solid solution with P-quartz structure, occurs after complete crystallization of TiZr04. HRTEM, Glass ceramic, Nucleating elements