Production and Characterization of Ag Nanoclusters Produced by Plasma Gas Condensation

Abstract

Silver nanoclusters were produced by plasma gas condensation method. The influence of argon flow and current density applied to Ag target on the size distribution of Ag clusters was evaluated. The clusters growth in the substrate was evaluated in static mode and rotation mode. The results indicate that the deposition in rotation mode leads to an increase in the clusters mean size while in static mode aggregation of Ag clusters represents the dominant growth mechanism. The crystalline structure of Ag clusters was evaluated by selected area diffraction patterns and X-ray diffraction, which suggested the formation of crystalline Ag. Scanning electron microscopy/energy dispersive spectrometry analysis of Ag films revealed the formation of porous Ag structures and no oxygen was found.

The role of gold atom concentration in the processes of formation of Cu-Au nanoparticles from the gas phase

“…In addition to this basic group, another five particles with a diameter of up to 6.5 nm were discovered, formed by agglomeration at sufficiently low temperatures. A similar pattern was observed by us at all used rates of heat energy removal, so this distribution can be considered basic, taking into account the fact that with an increase in the cooling rate, the maximum cluster size was expected to decrease in the simulated system in full accordance with experimental data [24].…”

“…Initially, the nucleus is formed as a result of the collision of two atoms of the atomized metal and one atom of an inert gas, which removes the excess kinetic energy. Further, the cluster can grow either in collision with other clusters or through the process of atomic condensation (clusters grow due to atoms falling on their surface) [24,25].…”

“…Conversely, an increase in pressure decreases the mean free path of atoms of a vaporized metal, thereby increasing the probability of collision between metal atoms or clusters, which, accordingly, leads to an increase in cluster size [24]. Also, in [2], using MD modeling based on bond-order potential using SiC2 nanoparticles as an example, it was shown that spherical clusters form, for the most part, at low cooling rates while cluster agglomerates form at high cooling rates.…”

Comparison of magnetron sputtering and gas aggregation nanoparticle source used for fabrication of silver nanoparticle films

“…In contrast, the utilization of GAS for deposition of Ag nanoparticle films makes it possible to vary their amount independently of their size. As proven by different research groups the size of the nanoparticles produced by GAS system may be in some range adjusted by the variation of operational parameters such as working gas, length of the aggregation chamber, pressure and flow of working gas or magnetron current [24,28,35].…”

“…This concept of gas aggregation sources was modified by Haberland et al [13], who substituted evaporation cell by a magnetron, which enabled the production of nanoparticles from materials with high melting point (details related to the GAS may be found in review articles [14][15][16]). These GAS systems were already used for the fabrication of a wide variety of metallic nanoparticles such as for instance Cu, Ti, Ag, and Al [17][18][19][20][21][22][23][24][25][26][27][28].…”