Plasma-chemical synthesis of nanocrystalline "core-shell" structures TiN-Mo-Co

Abstract

In this work, the possibilities of formation of nanocrystalline powders based on titanium nitride with participation of Mo and Co under conditions of plasma-chemical synthesis have been studied. Synthesis was performed according to the plasma recondensation scheme using low-temperature nitrogen plasma. All the obtained highly dispersed powders were certified by X-ray diffraction and scanning electron microscopy. The characteristics of the disperse composition of the recondensed TiN-Mo-Co products were determined by the calculation based on the pycnometric density and specific surface area data. The possibility of formation of a "core-shell" structure was confirmed using chemical methods by etching ultraand nanodispersed powders in solutions of dilute HCl to remove the cobalt shell and concentrated hydrogen peroxide H 2 O 2 to neutralize metallic Mo. Based on the information about "quasi-equilibrium state" of the products of plasma-chemical synthesis in a low-temperature gas plasma, a chemical model for the formation of nanocrystalline particles is proposed. KEYWORDS core-shell structure, titanium nitride, plasma-chemical synthesis, temperature barrier, phase formation ACKNOWLEDGEMENTS The authors are grateful to Dr. E. K. Dobrinsky, Ph. D., leading researcher of SSC RF JSC "GNIIChTEOS" for help in carrying out the plasma-chemical synthesis. The work was carried out in accordance with the state assignment for the Institute of Solid State Chemistry of the Ural Branch of the Russian Academy of Sciences (theme No 0397-2019-0003 "New functional materials for promising technologies: synthesis, properties, spectroscopy and computer simulation").