Effect of oxidation and heat treatment on the morphology and electronic structure of carbon-encapsulated iron carbide nanoparticles Fedoseeva, Yu.V., E-mail: jjulia@ngs.ru [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk (Russian Federation); Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation)]; Bulusheva, L G; Okotrub, A V [Nikolaev Institute of Inorganic Chemistry, Siberian Branch of Russian Academy of Sciences, 630090 Novosibirsk (Russian Federation)]; Novosibirsk State Technical University, 630092 Novosibirsk (Russian Federation)]; Vyalikh, D V [Institute of Solid State Physics, Dresden University of Technology, D-01062 Dresden (Germany)]; Junping, Huo; Huaihe, Song; Jisheng, Zhou; Xiaohong, Chen [State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, 100029 Beijing (China)] 36 MATERIALS SCIENCE; 77 NANOSCIENCE AND NANOTECHNOLOGY; ABSORPTION SPECTROSCOPY; AIR; ANNEALING; CARBONIZATION; ELECTRONIC STRUCTURE; EMISSION SPECTROSCOPY; FERROCENE; FINE STRUCTURE; GRAPHITE; IRON CARBIDES; IRON OXIDES; MORPHOLOGY; NANOSTRUCTURES; NITROGEN; PHASE TRANSFORMATIONS; TRANSMISSION ELECTRON MICROSCOPY; X-RAY DIFFRACTION; X-RAY SPECTROSCOPY Carbon-encapsulated iron carbide nanoparticles have been produced by co-carbonization of a mixture of an aromatic heavy oil and ferrocene at 450 Degree-Sign C under autogenous pressure. Transformations of the morphology and electronic structure of nanoparticles induced by air oxidation and subsequent heat treatment in a nitrogen atmosphere were examined using transmission electron microscopy, X-ray diffraction, near edge X-ray absorption fine structure spectroscopy, and X-ray emission spectroscopy. It was found that hollow nanoparticles, composed of iron oxides and oxidized carbon, were developed with thermal air oxidation of the initial product at 280 Degree-Sign C for 5 h. The mild oxidation of the product (250 Degree-Sign C for 3 h) followed by the carbonization at 500-550 Degree-Sign C yielded the hollow nanoparticles containing iron carbide/oxides and defective graphite-like carbon. The further annealing of nanoparticles at 1000 Degree-Sign C produced carbon nanocapsules with highly graphitized carbon walls and partially filled by spherical iron carbide nanoparticles. Highlights: Black-Right-Pointing-Pointer Fe{sub 3}C-C nanoparticles produced by co-carbonization of ferrocene and aromatic oil. Black-Right-Pointing-Pointer X-ray spectroscopy study of Fe{sub 3}C-C nanoparticles after oxidation and heat treatment. Black-Right-Pointing-Pointer Thermal oxidation of CENPs yields hollow Fe{sub 2}O{sub 3}/CO{sub x}. nanoparticles. Black-Right-Pointing-Pointer Annealing of Fe{sub 2}O{sub 3}/CO{sub x}. produces graphite-like carbon capsules filled with Fe{sub 3}C. Available from http://dx.doi.org/10.1016/j.matchemphys.2012.04.063 Netherlands 2012-07-16 English Journal Article Journal Name: Materials Chemistry and Physics; Journal Volume: 135; Journal Issue: 1; Other Information: Copyright (c) 2012 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA) Medium: X; Size: page(s) 235-240 https://doi.org/10.1016/J.MATCHEMPHYS.2012.04.063 PII: S0254-0584(12)00443-9 [] 1 135 Journal ID: ISSN 0254-0584; CODEN: MCHPDR; Other: PII: S0254-0584(12)00443-9; TRN: NL12S3888021020 NLN 2013-04-12 22061832