On the stress state of silver nanoparticles in ion-implanted silicate glasses

Soda-lime glasses were implanted with 1 x 10(16) and 2 x 10(16) Ag+ ions/cm (2) using an acceleration voltage of 200 kV. Size of silver particles forme d as well as their distribution within the implanted region and the structu re of these particles were analysed by transmission electron microscopy to describe interactions between the glass network and silver species. In agre ement with electron microscopy observation, RES measurements reveal a bimod al spatial distribution of Ag. This distribution, however, does not corresp ond to simple theoretical predictions. The lattice parameter changes of ind ividual Ag nanoparticles as determined from high-resolution electron micros copy images indicate the presence of strong compressive stresses acting on the particles which are caused by the surrounding glass matrix. The compres sive stress was approximated to 29 GPa, exceeding by far the elastic limit of the glass matrix. Therefore, a severe compression of the surrounding gla ss matrix is expected too, strongly affecting the migration and aggregation of silver, which results ill an unusual distribution of silver species. Th e observed difference between experimental and theoretical distribution of the implanted species can be explained in terms of these processes. (C) 200 0 Elsevier Science B.V. All rights reserved.