scholarly journals Mechanochemical synthesis of Co3C carbide with carbon nanotubes

2019 ◽  
Vol 20 (1) ◽  
pp. 13-17
Author(s):  
O. I. Nakonechna ◽  
M. M. Dashevski ◽  
A. M. Kurylyuk ◽  
N. M. Bilyavyna
Keyword(s):  
Crystal Structure ◽  
Carbon Nanotubes ◽  
Ball Mill ◽  
Diffraction Method ◽  
High Energy ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
Reliability Factor ◽  
X Ray ◽  
Reaction Milling

Nanoscaled (about 15 nm of size) metastable carbide Co3C was synthesized in a high-energy planetary ball mill by mechanical alloying of a mixture of powder cobalt (75 at. %) and multiwalled carbon nanotubes (CNT, 25 at. %). Phase transformation takes place at reaction milling according to the reaction hcp-Co + CNT ® Co3C (reaction time is 120 - 220 min). The crystal structure of the Co3C carbide formed in the milling products was studied by X-ray diffraction method. It has revealed that the Co3C phase crystallizes in a Fe3C-type structure with a = 0.4982(3) nm, b = 0.6715(6) nm, c = 0.4457(7) nm, Pnma space group. The reliability factor RB is equal to 0.065 for 48 reflections presented at diffraction pattern. It is found that the crystal structure of the Co3C carbide obtained by reaction milling of the Co-CNT charge is significantly internally deformed (distortion degree of the CCo6 octahedron is 3.67 %) and contains the reduced interatomic Co-C distances (up to 0.188 nm). It was shown that the use of carbon nanotubes instead of graphite substantially reduces the duration of the Co3C carbide synthesis.

scholarly journals Room-Temperature Synthesis of the TiC, ZrC, HfC, VC, NbC and TaC Powder Monocarbides

2019 ◽  
Vol 7 (1) ◽  
pp. 113-120
Author(s):  
Olesya I. Nakonechna ◽  
Nadezhda N. Belyavina ◽  
Mykola M. Dashevskyi ◽  
Yuriy A. Titov
Keyword(s):  
Crystal Structure ◽  
Mechanical Alloying ◽  
Ball Mill ◽  
Room Temperature ◽  
Diffraction Method ◽  
High Energy ◽  
Argon Atmosphere ◽  
X Ray Diffraction ◽  
Temperature Synthesis ◽  
X Ray

The nanoscaled (up to 30 nm) TiC, ZrC, HfC, VC, NbC and TaC monocarbides with NaCl-type structure have been synthesized from the elemental metals and the carbon nanotubes (CNTs) by mechanical alloying in a high energy planetary ball mill in an argon atmosphere. The powders obtained were examined by X-ray diffraction method. It is shown that mechanical alloying is accompanied by a decrease in the lattice parameters of MeC carbides formed and by a decrease of the total number of atoms in their crystal structure, i.e. by an increase of structural vacancies in the materials obtained. On the whole, monocarbides obtained can be arranged by the simplicity of their formation in a ball mill as: HfC -> ZrC -> TiC -> TaC -> NbC -> VC.

scholarly journals Novel Ti2CuCx and Ti3Cu2Cx Carbides Obtained by Sintering of Products of Mechanochemical Synthesis of Ti, Cu and Carbon Nanotubes

2019 ◽  
Vol 19 (2) ◽  
pp. 179-185 ◽  
Author(s):  
O.I. Nakonechna ◽  
N.N. Belyavina ◽  
M.M. Dashevskyi ◽  
K.O. Ivanenko ◽  
S.L. Revo
Keyword(s):  
Carbon Nanotubes ◽  
Ball Mill ◽  
Profile Analysis ◽  
Pure Titanium ◽  
Copper Particle ◽  
High Energy ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Full Profile ◽  
Elemental Powder Mixture

Mechanical alloying of the elemental powder mixture of titanium and copper (particle size of both powdersis about 40 μm, purity is not less than 99.6% wt. %) was performed in a high energy planetary ball mill to obtainTi:Cu (2:1 and 3:1) compositions. An addition of 1 vol. % of multiwalled carbon nanotubes (MWCNT, averagediameter 10-20 nm) into Ti-Cu charge results in a formation of nanoscaled Ti2CuCx and Ti3Cu2Cx carbides(containing 0.5 and 4.2 at.% of carbon and 30.8 and 37.5 at.% of copper, respectively). These carbides havesynthesized for the first time. Nature of interaction of the charge components at processing in a ball mill hasstudied on test samples using a complex of X-ray techniques. These techniques include a full-profile analysis forthe primary processing of diffractograms obtained with DRON-3M apparatus; qualitative and quantitative phaseanalysis for determining the phase composition of the products of synthesis; X-ray structural analysis to verifyand refine the structural models; Williamson-Hall method for determining the grain sizes. The Vickers hardnessof compacted (by sintering) samples with 20.1 and 27.3 at. % Cu varies substantially within (6.9-7.1) GPa. Thus,the average microhardness of synthesized materials is 7 times higher than that of pure titanium microhardness.

A New X‐Ray Diffraction Method for Studying Imperfections of Crystal Structure in Polycrystalline Specimens

1951 ◽  
Vol 22 (5) ◽  
pp. 665-672 ◽  
Author(s):  
Alfred J. Reis ◽  
Jerome J. Slade ◽  
Sigmund Weissmann
Keyword(s):  
Crystal Structure ◽  
Diffraction Method ◽  
X Ray Diffraction ◽  
X Ray

Synthesis of Nanocomposites of V2OO5©Selenium Nanoparticles and Multiwalled Carbon Nanotubes for Antimicrobial Activity

2021 ◽  
Vol 21 (11) ◽  
pp. 5673-5680
Author(s):  
Muthukrishnan Francklin Philips ◽  
Jothirathinam Thangarathinam ◽  
Jayakumar Princy ◽  
Cyril Arockiaraj Crispin Tina ◽  
Cyril Arockiaraj Crispin Tina ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Antimicrobial Activity ◽  
Multiwalled Carbon Nanotubes ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Functionalized Multiwalled Carbon Nanotubes ◽  
Uv Visible ◽  
Micro Organisms

The authors report the preparation of the nanocomposite comprising of vanadium pentoxide (V2O5) and selenium (Se) nanoparticles and functionalized multiwalled carbon nanotubes (MWCNTs) (V2O5@Se NPs/MWCNTs). Since Se NPs possesses extraordinary physicochemical properties including larger surface area with higher adsorption capacity, V2O5 NPs were adsorbed onto Se NPs surface through physisorption process (designated as V2O5@Se NPs). The nanocomposite synthesized hydrothermally was evaluated for its antimicrobial activity. The morphology and microstructure of the nanocomposite were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis, respectively. Fourier transform infrared spectroscopy (FTIR) and UV-Visible spectroscopy (UV-Vis) were employed to analyze the spectral properties of nanocomposite. The microbicidal efficacy of nanocomposite was tested against Gram-negative (G-)ZGram-positive (G+) bacteria and fungus. This is the first report on the synthesis of V2O5@Se NPs/MWCNTs nanocomposites by chemical method that showed microbicidal effect on micro-organisms. The thiol (-SH) units facilitates the enrichment of V2O5@Se NPs onto MWCNTs surface. Ultimately, it reflects on the significant antimicrobial activity of V2O5@Se NPs/MWCNTs.

scholarly journals Magnetically Oriented Powder Crystal to Indexing and Structure Determination

2014 ◽  
Vol 70 (a1) ◽  
pp. C1560-C1560
Author(s):  
Fumiko Kimura ◽  
Wataru Oshima ◽  
Hiroko Matsumoto ◽  
Hidehiro Uekusa ◽  
Kazuaki Aburaya ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Single Crystal ◽  
Crystal Lattice ◽  
Powder Diffraction ◽  
Diffraction Method ◽  
Lattice Parameters ◽  
X Ray Diffraction ◽  
X Ray ◽  
Crystal Lattice Parameters

In pharmaceutical sciences, the crystal structure is of primary importance because it influences drug efficacy. Due to difficulties of growing a large single crystal suitable for the single crystal X-ray diffraction analysis, powder diffraction method is widely used. In powder method, two-dimensional diffraction information is projected onto one dimension, which impairs the accuracy of the resulting crystal structure. To overcome this problem, we recently proposed a novel method of fabricating a magnetically oriented microcrystal array (MOMA), a composite in which microcrystals are aligned three-dimensionally in a polymer matrix. The X-ray diffraction of the MOMA is equivalent to that of the corresponding large single crystal, enabling the determination of the crystal lattice parameters and crystal structure of the embedded microcrytals.[1-3] Because we make use of the diamagnetic anisotropy of crystal, those crystals that exhibit small magnetic anisotropy do not take sufficient three-dimensional alignment. However, even for these crystals that only align uniaxially, the determination of the crystal lattice parameters can be easily made compared with the determination by powder diffraction pattern. Once these parameters are determined, crystal structure can be determined by X-ray powder diffraction method. In this paper, we demonstrate possibility of the MOMA method to assist the structure analysis through X-ray powder and single crystal diffraction methods. We applied the MOMA method to various microcrystalline powders including L-alanine, 1,3,5-triphenyl benzene, and cellobiose. The obtained MOMAs exhibited well-resolved diffraction spots, and we succeeded in determination of the crystal lattice parameters and crystal structure analysis.

scholarly journals Fabrication of MoS2 Nanoflakes Supported on Carbon Nanotubes for High Performance Anode in Lithium-Ion Batteries (LIBs)

2019 ◽  
Vol 2019 ◽  
pp. 1-7
Author(s):  
T. Minh Nguyet Nguyen ◽  
Vinh-Dat Vuong ◽  
Mai Thanh Phong ◽  
Thang Van Le
Keyword(s):  
Carbon Nanotubes ◽  
Lithium Ion Batteries ◽  
High Performance ◽  
Lithium Ion ◽  
Interlayer Spacing ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
X Ray ◽  
Functionalized Multiwalled Carbon Nanotubes ◽  
20 Nm

Molybdenum disulfide (MoS2), an inorganic-layered material similar to structure of graphite, was randomly dispersed onto the surface of functionalized multiwalled carbon nanotubes to synthesized nanocomposite MoS2/CNT. The as-obtained product was characterized via SEM, TEM, TGA, X-ray diffraction, and Raman spectroscopies. It was confirmed from XRD that MoS2 layers with interlayer spacing of 0.614 nm were successfully produced. TEM images and Raman spectra indicated a random distribution of 20 nm sized nanoflake MoS2 on the surface of MWNTs. The electrochemical performance of materials are expected to pave the way for the utilized anode material for lithium-ion batteries.

X-ray diffraction study of the evolution of Fe-filled multiwalled carbon nanotubes under pressure

2009 ◽  
Vol 72 (1) ◽  
pp. 145-151 ◽  
Author(s):  
J. Cambedouzou ◽  
V. Heresanu ◽  
C. Castro ◽  
M. Pinault ◽  
F. Datchi ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Diffraction Study ◽  
Multiwalled Carbon Nanotubes ◽  
X Ray Diffraction ◽  
Multiwalled Carbon ◽  
X Ray
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