Microstructure and silver nanoparticles in ion-exchanged and deformed soda-lime silicate glasses

Optical absorption, microspectrophotometry, thermally stimulated depolarization current, and transmission electron microscopy were applied to a commercial multicomponent soda-lime silicate glass subjected to the Na+⇔Ag+ ion-exchange, annealing in air or hydrogen, and to mechanical stretching. The treatments affect both the matrix microstructure and the morphology of the silver particles. Mechanical stretching of the exchanged specimens annealed in hydrogen induces the most interesting effects. Secondary phase separation occurs within the glassy matrix, and causes drastic changes of the thermocurrent data, which are interpreted in terms of the Maxwell–Wagner interfacial polarization. Elongation of the spherical silver nanoparticles produces a remarkable dichroism of the optical absorption, which could be exploited for new applications. The sample stretching affects only particles with a diameter larger than 5 nm interpreted as a threshold size, at least at the stresses used in the present work.