Synthesis of Tantalum Nitride Nanoparticles With Different Nitridation Atmosphere in Induction Thermal Plasma

Tantalum nitride nanoparticles were successfully synthesized by induction thermal plasma. The nitrogen sources were controlled to investigate the impacts on nitridation process in thermal plasma. The chemical composition and morphology of the final product were detected by X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. The formation mechanism was clarified based on the calculation of nucleation temperature and Gibbs free energy change. Tantalum first nucleates at about 3700 K due to the highest nucleation temperature. The nitridation of Ta nuclei is promoted when nitrogen sources change from N<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> molecules to NH radicals. Products transition from oxides and nitrogen-deficient compound Ta<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>N mixture to TaN<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">x</sub> with a Ta to N stoichiometric ratio close to 1:1, based on the analysis and calculation result. The amount of nitrogen vacancies in the product can also be effectively controlled by adjusting the injected NH radical concentration. Induction thermal plasma provides a progressive mean to industrial produce nanomaterials applied in the field of advanced coating materials.