Silver Nanoparticles in Oxide Glasses: Technologies and Properties

Abstract

Intr"ducti"nNano-size particles of noble metals (Ag, Au, Pt) are today a subject of thorough attention of scientific researchers and of technologists, because these particles reveal the wide range of physical features, absent in the case of bulk media. Size-controlled optical properties of Ag-nanoparticles open good prospects for potential technological applications -such as diffraction elements, optical filters, nanoplasmonic devices, bi-sensors, and nonlinear media. Silver nanoparticles can be produced in various media -in water solutions, in polymers, in glasses, and in crystalline media. For instance, the long period in photographic imaging technique was based on the photoinduced production of Ag nanoclusters in the crystals of AgHal (the latent image). At the same time one can say that the inorganic glasses are the unique matrix for silver nanoparticles formation. The wide temperature range of glass viscosity growth provides the possibility to control over the Ag nanoparticles size within the wide range by means of modifying the temperature and duration of thermal processing. In the fact, only such kind of matrix makes it possible to control and investigate all the stages of Ag nanoparticles formation, including the starting stage. Glass coloring by introduction of the metallic Ag nanoclusters is one of the ancient methods, known by humanity [1]. The mechanisms, leading to nucleation and growth of such nanoclusters, are the scientific and technology problem, important both for colored glass production and for all other potential applications of glass with silver nanoparticles [2][3][4][5]. The researches on silver nanoclusters formation comprise numerous technical approaches. Especially interesting are the methods, based on the use of ionizing radiation, are especially interesting due to their ability provide either local irradiation or to irradiate the whole volume of the glass. In this case it is comparatively simple to provide the control over concentration and average size of metallic nanoclusters. For instance, the controlled photon irradiation is used for production of photosensitive [6], polychrome [м] and photo-thermorefractive [н] glasses. Very often all these types of glasses are called the photosensitive one (PS). Further within this chapter we shall use this word. 10www.intechopen.com

Saturable absorption of silver nanoparticles in glass for femtosecond laser pulses at 400 nm

“…Small aggregates (such as Ag-pairs, trimers) can be understood as intermediate species before the precipitation of metallic NPs. Their presence suggests that post-exchange annealing led to increase the size of the molecule of nucleus Ag 0 into silver NPs Ag n as follows: Ag 0 → Ag 2 + → Ag 3 + /Ag 3 2+ → ⋯ → Ag n [39]. The observed PL behavior can be related to a progressive Ag aggregation as it was observed in [35,40].…”

New insight into nanoparticle precipitation by electron beams in borosilicate glasses

“…Vostokov et al [32] reported the capability of the electron beam irradiation in the formation of 2D metallic nanostructures in Ag and Cu-doped glasses. Studies on the formation of silver nanoparticles of various diameters in glasses under low-energy electron beam irradiation have been reported by Nikonorov et al [14,[32][33][34][35] and Brunov and co-workers [36]. These studies concentrate on general charge-induced surface aggregation observed ex situ by light microscopy without nanoscale imaging of the actual particle-enriched glass surface.…”

“…A variety of methods have been used to prepare nanoparticles in oxide glasses, ranging from the standard annealing processes, or sol-gel preparation, over ion-exchange by diffusion, ion implantation, to irradiation with photon or particle beams [13][14][15][16][17][18][19][20][21][22]. Amongst the latter, laser irradiation [23,24] is the most established technique in particular for the precipitation of copper and silver nanoparticles in glass.…”

The formation of silver nanoparticles on the surface of silver-containing glasses when they are irradiated with nanosecond laser pulses

“…The shift of the maximum of the plasmon absorption band to λ 420 nm indicates that the silver nanoparticle is surrounded by a dielectric shell with n ≈ 1.5 (see, for example, Ref. 25).…”