Synthesis of silver nanoparticles in glasses by ion implantation and study of their optical properties

Synthesis of metal nanoparticles (NP) in SiO2 by implantation of Ag+ ions with energy of 30 keV is studied depending on the dose ((2-8)·1016 cm-2) and ion current density (4-15 mA/cm2). Optical spectroscopy and atomic force microscopy (AFM) are used for the analysis of the produced composite materials. The NP synthesised in glass show a characteristic optical absorption band related to the effect of surface plasmon resonance. Correlation between a shift of the spectral bands caused by a change in the NP size and diameter of hemispherical protrusions on the glass surface observed by AFM is found. For the case of fixed ion current density, the NP size is found to be almost constant with elevation of the dose up to a certain value (of 6·1016 cm-2). In this case an increase in the concentration of NP is observed only. However the further elevation of the dose leads to the decrease of both the concentration and size. On the other hand at a fixed high dose, the increase of the ion current density causes the gradual enlargement of NP. The mechanisms accounting for the change in NP size with elevation of the dose and ion current density are analysed. Possibility of controllable synthesis of the metal NP using various regimes of ion implantation is discussed. (authors)