Synthesis of Silicon Carbide Nano-Powder from a Silicon-Organic Precursor by RF Inductive Thermal Plasma

Abstract

Silicon carbide (SiC) has recently drawn an enormous amount of industrial interest due to its useful mechanical properties, such as its thermal resistance, abrasion resistance and thermal conductivity at high temperatures. In this study, RF thermal plasma (PL-35 Induction Plasma, Tekna CO., Canada) was utilized for the synthesis of high-purity SiC powder from an organic precursor (hexamethyldisilazane, vinyltrimethoxysilane). It was found that the SiC powders obtained by the RF thermal plasma treatment included free carbon and amorphous silica (SiO 2). The SiC powders were further purified by a thermal treatment and a HF treatment, resulting in high-purity SiC nano-powder. The particle diameter of the synthesized SiC powder was less than 30 nm. Detailed properties of the microstructure, phase composition, and free carbon content were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), a thermogravimetric (TG) analysis, according to the and Brunauer-Emmett-Teller (BET) specific surface area from N2 isotherms at 77 K.

Crystal Structure, Microstructure and Mechanical Properties of NbN Coatings Deposited by Asymmetric Bipolar Pulsed DC Sputtering

“…In the present experiment, the grain size was calculated by using the Scherrer method, and the grain size was reduced with an increase in the half width. 18) As can be seen from the figure, the grain size of NbN coatings can be seen to be consecutively reduced from 52.7 nm under the condition 1, to 31.4 nm under the condition 2, to 28.7 nm under the condition 3, and then to 27.5 nm under the condition 4. Consequently, generation conditions for the pulse plasma resulting from the use of asymmetric bipolar pulse sputtering can be seen to be a very important process variable as a technique to control the microstructures of NbN coatings.…”