Formation of Ni₃C Nanocrystals by Thermolysis of Nickel Acetylacetonate in Oleylamine: Characterization Using Hard X-ray Photoelectron Spectroscopy

Abstract

Nickel acetylacetonate was thermally decomposed in oleylamine under inert atmosphere. Nanocrystals of two cubic phases and a hexagonal phase appeared. The phases were identified using X-ray diffraction, laboratory X-ray photoelectron spectroscopy (XPS), and hard-X-ray photoelectron spectroscopy (HX-PES). The hexagonal phase was a nickel carbide, Ni3C, which had been often identified as a hexagonal close-packed metallic nickel. One cubic phase was a face-centered metallic nickel, and the other cubic phase was proposed as a novel cubic nickel carbide, which was characterized as an intermediate product of the carbidization of metallic face-centered cubic Ni to the hexagonal nickel carbide.

Shape control of nickel nanostructures incorporated in amorphous carbon films: From globular nanoparticles toward aligned nanowires

“…4(a)). The first one located at 283.5 eV (labelled C1) can be attributed to the carbon atoms bonded to the nickel ones (Ni-C) present in a sub-stoichiometric Ni 3 C phase, [59][60][61][62] which is called NiC x (with x 0.33). The second component at 284.5 eV (labelled C2) can be attributed to the carbon atoms present in an amorphous carbon phase.…”

Synthesis of Ni Carbide Nanoparticles with Ni₃C-Type Structure in Polyol Solution Containing Dispersant

“…24,25) In addition, such peaks has been observed recently in the X-ray diffraction pattern of Ni carbide nanoparticles with the Ni 3 C-type structure precipitated in the solution, 23) although these are not indicated in the X-ray diffraction pattern in the ICDD database. 12,17) Thus the X-ray powder diffraction pattern for the specimen synthesized with 50 g/L PVP was analyzed by Rietveld analysis by using the structure model of Ni 3 C mentioned above. The refined results of the Rietveld analysis are shown in Fig.…”

“…717,20,23) The hexagonal phase has been characterized as Ni carbide with a Ni 3 C-type structure by some investigations using X-ray diffraction, 11,14,16,19,21,23) high-resolution transmission electron microscopy 14,20,22,23) and hard X-ray photoelectron spectroscopy. 11,12) However, the hexagonal phase has been identified as metallic Ni by several investigations. 810,13,15) In other words, it is still controversial as to whether the hexagonal phase is Ni carbide or metallic Ni in many investigations because the X-ray diffraction pattern in the International Center for Diffraction Data (ICDD) database of the former is very similar to that of the latter.…”

“…810,13,15) In other words, it is still controversial as to whether the hexagonal phase is Ni carbide or metallic Ni in many investigations because the X-ray diffraction pattern in the International Center for Diffraction Data (ICDD) database of the former is very similar to that of the latter. 12,17) It is required to establish the synthesis condition of hexagonal phase and to characterize it in detail.…”

Controlled Growth of a Hierarchical Nickel Carbide “Dandelion” Nanostructure

“…Goto et al prepared Ni 3 C dots by thermolysis of nickel acetylacetonate in oleylamine. [11] Sarac et al investigated the branching of Ni 3 C 1Àx NCs. [12] Herein we report the synthesis of a hierarchical nonporous Ni 3 C structure with high specific surface area by thermal decomposition of an organometallic Ni precursor in a mixture of ligands in a noncoordinating solvent.…”