Formation of ultrafine β-silicon carbide powders in an argon thermal plasma jet

Abstract

Ultrafine /3-silicon carbide powders are synthesized in a thermal plasma jet, generated with a swirl-stabilized plasma torch, using methane and silicon monoxide as reactants. High temperatures (>10000 K) combined with ultrarapid quench rates (>106 K/s) lead to a high degree of supersaturation, resulting in homogeneous nucleation of ultrafine SiC particles. The maximum conversion of SiO to SiC determined by thermogravimetric analyses is 97.3%. Particle size analyses show a bimodal distribution with the majority of the particles falling in a size range from 2 to 40 nm. Larger particles with sizes greater than 80 nm are also observed. Triangular and hexagonal SiC single-crystal platelets are observed throughout this work, and the formation of these particles is discussed in this paper.

Controlled Synthesis of β-SiC Nanopowders with Variable Stoichiometry Using Inductively Coupled Plasma

“…Another approach is to create a plasma to obtain the decomposition of a precursor that can be gaseous, liquid or solid. Different groups around the world have developed such techniques, using different types of precursors (SiO 2 + CH 4 , Si anode + CH 4 , coarse SiC...) or plasma source (transfer arc, DC or RF thermal plasma...) [19][20][21][22][23][24][25]. One of the tricky parts concerning the use of powders as a precursor is to manage to introduce the powder inside the dense plasma.…”

Synthesis of Uniform α-Si3N4 Nanospheres by RF Induction Thermal Plasma and Their Application in High Thermal Conductive Nanocomposites

“…In vapor synthesis process, supersaturation plays a key role in the particle size and distribution. 38 Under high supersaturations of chemical species, nucleation rate increased, and large numbers of nuclei formed and exhausted most of the nutrient, leading to undernutrition for nuclei growth process. Together with the homogeneous growth, it results in small particle size.…”

Synthesis of Silicon Carbide Dendrite by the Arc Plasma Process and Observation of Nanorod Bundles in the Dendrite Arm

“…In the literature of carbothermic synthesis carried out in electric arc and thermal plasma, one finds that Si( l ) participation in SiC growth has been highlighted by several workers. Kuhn 3 and Kong and Pfender 5 have studied the SiC preparation under electric arc and thermal plasma jet, respectively, and concluded that liquid phase growth of SiC occurs by the following multi step reaction: …”