Electron microscopic study on nucleation and growth of silver particles in a thin glass film

Abstract

Nucleation and crystal growth of silver particles in a thin glass film of Li 2O·2.6SiO 2 glass containing 0.1 wt% of Ag 2O were observed by transmission electron microscopy and studied by an electron diffraction technique. Anomalies of the image contrast which appeared in the heat-treated specimens were explained to be caused by phase separation of the glass. Nucleation of silver particles was found to occur on the surface of the phase-separated silica-rich droplets. As the silver particles grew, their shape changed into that of a regular cube which was covered with a thin diffusion layer of silver ions about 50 Å in thickness. The presence of this thin layer and the cubic shape suggest that the growth of silver particles proceeds by a layer-by-layer growth mechanism.