Formation of complex titanium-nickel nitride Ti0.7Ni0.3N in the “core-shell” structure of TiN – Ni

Abstract

Nanocrystalline “core-shell”-structures are of much interest in different areas of solid state chemistry and materials science since in the process of synthesis composite materials can be formed, whose phase components cannot coexist within a single boundary of composite material. The aim of the proposed research is to obtain, certify and refine the localized states of the complex titanium-nickel nitride Ti0.7Ni0.3N as part of a TiN-Ni nanocrystalline composite having a “core-shell” structure.The titanium-nickel powder was processed under the conditions of plasma-chemical synthesis according to the plasma recondensation scheme in a low-temperature (4000–6000°С) nitrogen plasma. The plasma recondensation method implies the separation of synthesis products into differently dispersed fractions caught by classifiers in the form of a vortex-type cyclone (classifier 1) and a bag-type fabric filter (classifier 2). All the recondensed nanomaterials were passivated during synthesis in the encapsulation unit included in the plasma chemical installation. The TiN – Ni nanocrystalline composition, having a “core-shell”-structure, condenses during the interaction of initial precursors evaporated in the plasma torch with their subsequent condensation of gaseous nitrogen in a rotating cylinder, which was established by instrumental structural-morphological studies using X-ray diffraction and scanning electron microscopy and high resolution transmission electron microscopy. A complex titanium-molybdenum nitride Ti0.7Ni0.3N of hexagonal modification was recorded radiographically in the same fraction of nanocrystalline particles. Moreover, the Ti0.7Ni0.3N nitride was in a highly deformed stress state, as evidenced by the presence of a single reflex (101). In this work, the structural state of the three-component Ti0.7Ni0.3N titanium-nickel nitride was established by X-ray diffraction and high-resolution transmission electron microscopy (HRTEM) and the main phase and structural components of the nanocrystalline composition were certified.