Synthesis and characterization of the novel nanostructured NiC carbide obtained by mechanical alloying

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Japan, 2022-02, Vol.33 (2), p.103390, Article 103390
• Main Authors: Ostapenko, R., Ivanenko, K., Kuryliuk, A., Nakonechna, O., Belyavina, N.
• Format: Article
• Language: English
• Subjects: Carbon nanotube; Crystal structure; Magnetic susceptibility; Mechanical alloying; X-ray diffraction
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2021.12.009

[Display omitted] •Fcc NiC monocarbide was synthesized by milling of nickel and CNT/graphite charge.•A two-step carbide formation mechanism has been proposed.•Associated changes in the nickel lattice were evaluated and discussed.•Allotropic form of carbon used makes an impact on NiC crystal structure.•Magnetic moment per nickel atom (2.83μB) is higher than that of a bulk Ni (1.3μB). In the present work, a comprehensive study of mechanical alloying of Ni-carbon nanotubes (CNT) and Ni-Graphite equiatomic powder mixtures under the same technological modes has provided to reveal the features of using different types of carbon (CNT or graphite) as a charge component. The as-milled powders were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and magnetometric study. A novel nanoscale fcc NiC monocarbide was synthesized regardless the type of the charge used. According to the XRD study the formation of this phase takes place in two stages. A two-step carbide formation mechanism has been proposed. The associated changes in the nickel lattice, such as changes in the lattice parameter, lattice strain and residual stresses, which led to the formation of NiC monocarbide were also evaluated and discussed. Parameters of the electronic structure of NiC were calculated using the MStudio MindLab 7.0 software package with the experimental data on the crystal structure of the NiC phase obtained as input. Temperature dependencies of magnetic susceptibility of NiC synthesized have been studied up to 950 K. Carbides synthesized were found to be weak ferromagnets at the room temperature and their Curie temperature TC ranges within 670 – 725 K. The calculated value of the magnetic moment per nickel atom (2.83μB) is higher than that of a bulk Ni (1.3μB). Likely, the observed increase of μ is caused by the presence of a certain amount of residual single-domain ferromagnetic Ni nanoparticles in the samples synthesized.