Development of Nanopowder Synthesis Using Induction Plasma

Abstract

The application of induction plasma technology developed for the synthesis of nanometric powders is summarized. A brief description of the scientific basis for the induction plasma processes is given, followed by the presentation of an induction plasma system developed by Tekna, together with various examples of the nanopowders synthesized using its facilities. The advantages of the induction plasma process over alternative techniques and its adaptability into industrialscale operation is particularly illustrated. Some specific issues related to the nanopowder synthesis process are also discussed.

Growth Mechanisms of Inductively-Coupled Plasma Torch Synthesized Silicon Nanowires and their associated photoluminescence properties

“…The occurrence of the OAG mechanism during the ICP synthesis can be delineated as follows. Inside the ICP reactor the Si feedstock is partially sublimated29 and the resulting highly reactive vapor actively interacts with oxygen present in the reactor. The oxygen originates mainly from the native oxide layer at the surface of Si feedstock powder which is partially released during the spheroidization process (it is commonly observed that powders processed by ICP exhibit enhanced purity as compared to feedstock30).…”

“…Theoretical models have shown that hot vapors of Si and O are largely constituted of silicon suboxide clusters, which are highly reactive and tend to bond with other clusters19. Given the non-equilibrium conditions in the ICP reactor29, it is highly likely that the spheroidization occurs while some remaining hot vapors are present in the chamber. Concurrently, these SiNSs can act as substrate onto which other SiNWs can grow according to the OAG model, as schematically sketched in Fig.…”

Formation of silicon nanocrystal chains induced via Rayleigh instability in ultrathin Si/SiO2 core/shell nanowires synthesized by an inductively coupled plasma torch process

“…The fast Fourier transform (FFT) in the insets of the figures 1(d) and (e) corresponds to the very thin crystalline SiNWs, which may feature the cylindrical configuration ( figure 1(d)) or connect the almond-shaped SiNCs (figure 1(e)). The presence of these different families of Si nanostructures in the ICP-synthesized Si nanopowder results, a priori, from the temperature gradient and residence time of the silicon species in the hot plasma region of the ICP torch [27]. In fact, many concomitant phenomena occur during the complex ICP synthesis process, which makes it difficult to single out the effect of the temperature on the synthesized Si nanostructures.…”

Preparation of Nano Aluminium Powder (NAP) using a Thermal Plasma: Process Development and Characterization

“…Various techniques are used to prepare NAP and these are divided into high temperature and low temperature processes. The high temperature techniques include gas evaporation [13][14][15][16], plasma chemical synthesis [17][18][19][20][21][22], laser ablation [23], arc discharge [24][25][26], electro-explosion [27][28][29][30], and ion implantation [31], whereas the low temperature techniques include solution methods [32][33][34][35][36][37][38] and mechanical attrition (ball milling) [39][40]. However, producing bulk NAP continues to be a technical challenge.…”