Carbothermal Synthesis of Cr3C2-WC-Ni Nanocomposite Powders

2013 ◽  
Vol 661 ◽  
pp. 3-6 ◽  
Author(s):  
Yong Zhong Jin ◽  
Fa Ming Ye ◽  
Xian Guang Zeng ◽  
Rui Song Yang
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Carbothermal Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbothermal Synthesis ◽  
Unit Cells ◽  
Nanocomposite Powders ◽  
Scanning Electron

Cr3C2-WC-Ni nanocomposite powders with ~50-100 nm were synthesized from precursors by vacuum-aided carbothermal reduction at only 750 °C for 2 h. The phase composition and microstructure of the synthesized products were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The present study shows that Cr3C2-WC-Ni nanocomposite powders contain two kinds of solid-solution phases, namely Ni and (Cr, W)3C2solid solution, respectively. WC and W2C phases do not appear inreaction products due to the dissolution of tungsten atoms into Ni and Cr3C2unit cells. Especially, there is a change of the crystalline structure for (Cr, W)3C2phase from 750 °C to 800 °C.

Biomorphic SiC Prepared from Carbonized Millet by Sol-Gel and Carbothermal Reduction Processing

2010 ◽  
Vol 152-153 ◽  
pp. 1683-1686
Author(s):  
Qing Wang ◽  
Ya Hui Zhang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Silicon Carbide ◽  
Phase Composition ◽  
Carbothermal Reduction ◽  
Sol Gel ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Template ◽  
Scanning Electron

Biomorphic silicon carbide (bioSiC) was prepared by high temperature pyrolysis and sol-gel and carbothermal reduction processing at 1600 oC. The morphology and microstructure of carbon-silica composites and purified bioSiC samples were characterized by scanning electron microscopy. The phase composition of the resulting sample was analyzed by X-ray diffraction. The results suggest that the bioSiC mainly consists of cubic ß-SiC, and principally replicates the shape and microstructure of the carbon template.

Synthesis of Ti3Si0.4Al0.8C1.8 Solid Solution

2008 ◽  
Vol 368-372 ◽  
pp. 995-997
Author(s):  
Cui Wei Li ◽  
Hong Xiang Zhai ◽  
Yang Zhou ◽  
Shi Bo Li ◽  
Zhi Li Zhang
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Single Phase ◽  
Lattice Parameters ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Powder Mixtures ◽  
X Ray ◽  
Scanning Electron

In this study, free Ti/Si/Al/C powder mixtures with molar ratio of 3:0.4:0.8:1.8 were heated in Argon with various schedules, in order to reveal the possibility for the synthesis of Ti3Si0.4Al0.8C1.8 solid solution powder. X-ray diffraction (XRD) was used for the evaluation of phase identities of the powder after different treatments. Scanning electron microscopy (SEM) was used to observe the morphology of the Ti3Si0.4Al0.8C1.8 solid solution. XRD results showed that predominantly single phase samples of Ti3Si0.4Al0.8C1.8 was prepared after heating at 1400oC for 5 min in Argon and the lattice parameters of Ti3Si0.4Al0.8C1.8 lay between those of Ti3SiC2 and Ti3AlC2.

Effects of V2O5 on the synthesis of Ba2Ti9O20 powders

2005 ◽  
Vol 20 (10) ◽  
pp. 2741-2744 ◽  
Author(s):  
Huixing Lin ◽  
Wei Chen ◽  
Lan Luo
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Single Phase ◽  
X Ray Diffraction ◽  
Eutectic Liquid ◽  
X Ray ◽  
Intermediate Phases ◽  
Phase Pure ◽  
Scanning Electron

Phase-pure Ba2Ti9O20 powders were made by doping 3 wt% of V2O5 to a Ba:Ti = 2:9 molar composition, and the effects of the dopant on the phase formation were investigated. The study shows that BaTiO3, BaTi2O5, and BaTi4O9 were the intermediate phases before the formation of Ba2Ti9O20 for samples with or without V2O5. However, with V2O5 doping, the temperature at which Ba2Ti9O20 occurred were lowered from 1150 to 1050 °C and single phase Ba2Ti9O20 powders was easily obtained at 1150 °C for 2 h. Microstructure of the powders was examined by field emission scanning electron microscopy. No evidence of V2O5–Ba2Ti9O20 solid-solution was found by x-ray diffraction and energy-dispersive spectroscopy. The benefit of V2O5 to facilitate the Ba2Ti9O20 synthesis is most probably due to a vanadium-containing eutectic liquid phase which accelerates the migration of reactant species.

Microwave-Assisted Preparation of Cu2O Octahedral Microcrystals

2011 ◽  
Vol 284-286 ◽  
pp. 746-749
Author(s):  
Chong Hai Deng ◽  
Han Mei Hu ◽  
Ming Di Yang
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Growth Mechanism ◽  
X Ray Diffraction ◽  
Chemical Route ◽  
X Ray ◽  
Microwave Assisted ◽  
Morphology And Structure ◽  
Scanning Electron

In this paper, we reported a facile microwave-assisted green chemical route to prepare pure, uniform, and monodispersed Cu2O octahedron wrapped by the {111} faces by using glucose as a reducing agent. X-ray diffraction (XRD), energy dispersive X-ray spectrometry(EDX) and field emission scanning electron microscopy (FESEM) were used to characterize the as-synthesized products. It was found that the morphology and structure of Cu2O crystals were greatly affected by the concentration of NaOH. A solid-solution-solid growth mechanism was possibly proposed on the basis of the comparative experimental results.

Investigation on the Structural Properties of a New Prepared 0.2PZS-0.8PLZT Ceramics

2013 ◽  
Vol 856 ◽  
pp. 197-200
Author(s):  
Adel Sakri ◽  
Ahmed Boutarfaia
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Smart Materials ◽  
Sintering Temperature ◽  
Human Life ◽  
Advanced Technology ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

View of the importance that has the development in the field of advanced technology transmission in human life, smart materials draws the attention of many researchers. In this contribution, we are interested in synthesizing a new smart material of the ceramic type based on Pb, Zr, Ti (PZT) doped La in the site A, and Sb, Zn in site B from a solid solution of pure oxides. The synthesized samples are thermally treated at 800°C. The techniques of x-ray diffraction (XRD) and SEM (scanning electron microscopy) are used to characterize the microstructure (the crystallographic phase), and the densities of the obtained samples were determined from their weights and volumes. The effect of sintering temperature on the microstructure properties was studied.

Microstructural and Dielectrical Properties for Ceramics and Thin Films of the xPbTiO3-(1−x)SrTiO3 Solid Solution

2001 ◽  
Vol 688 ◽  
Author(s):  
E. Martínez ◽  
A. Fundora ◽  
O. Blanco ◽  
S. García ◽  
E. Heredia ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Dielectric Properties ◽  
Integrated Circuit ◽  
X Ray Diffraction ◽  
X Ray ◽  
Analysis Technique ◽  
Dielectrical Properties ◽  
Scanning Electron

AbstractSrTiO3 and PbTiO3 perovskites are combined to form the xPbTiO3-(1−x)SrTiO3 (PST) solid solution. The effect of the PbTiO3 content on the microstructural and dielectric properties is studied for different compositions (x=0.1,0.3,0.5,0.7, and 0.9). Microstructural features of the PST system are studied by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM) techniques. Electrical properties are studied by the thermoelectric analysis technique at both fixed frequency and varying frequency to study the behavior of the dielectric constant and dielectric loss.Films of 0.5PbTiO3-0.5SrTiO3 (PST50) have been obtained by RF ion sputtering on different substrates. We investigate the relation between the crystalline structure and the dielectric properties of PST50 films deposited on different metallic films. Scanning Electron Microscopy (SEM) and X-Ray Diffraction were used for the structural analysis of the PST50/TiN/Si and PST50/RuO2/TiN /Si systems. The dielectric properties of the PST50 films were measured for TiN/PST50/TiN/Si, and RuO2/PST50/RuO2/TiN/Si capacitors and the results were correlated to the structure and composition. The charge storage capabilities of the PST50 films are evaluated for possible application in integrated circuit technology.

scholarly journals Preparation of biomorphic SiC ceramics

2008 ◽  
Vol 40 (2) ◽  
pp. 141-145 ◽  
Author(s):  
A. Egelja ◽  
J. Gulicovski ◽  
A. Devecerski ◽  
M. Ninic ◽  
A. Radosavljevic-Mihajlovic ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Carbothermal Reduction ◽  
Oxide Ceramic ◽  
X Ray Diffraction ◽  
X Ray ◽  
Carbon Preform ◽  
Sic Ceramics ◽  
Porous Sic ◽  
Scanning Electron

This paper deals with a new method for producing non-oxide ceramic using wood as a template. SiC with a woodlike microstructure has been prepared by carbothermal reduction reactions of Tilia wood/TEOS composite at 1873K. The porous carbon preform was infiltrated with TEOS (Si(OC2H5)4), as a source of silica, without pressure at 298K. The morphology of resulting porous SiC ceramics, as well as the conversion mechanism of wood to SiC ceramics, have been investigated by scanning electron microscopy (SEM/EDS) and X-ray diffraction analysis (XRD). Obtained SiC ceramics consists of ?-SiC with traces of ?-SiC.

Zirconolite-Based Ceramic Formulations for Immobilization of Zr-REE-Actinide Fraction of HLW

2004 ◽  
Vol 824 ◽  
Author(s):  
A.V. Ochkin ◽  
S.V. Stefanovsky ◽  
A.G. Ptashkin ◽  
N.S. Mikhailenko ◽  
O.I. Kirjanova
Keyword(s):  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
High Level Waste ◽  
X Ray Diffraction ◽  
Controlled Cooling ◽  
X Ray ◽  
Transmission Electron ◽  
High Level ◽  
Scanning Electron

AbstractTwo ceramics for immobilization of a Zr-REE-actinide fraction of high level waste (HLW) based on zirconolite or/and pyrochlore structures with minor brannerite/lucasite, and fluorite-structured dioxide-based solid solution, were synthesized and characterized. The samples were produced by melting of oxide mixtures at 1500 °C followed by controlled cooling for crystallization. Phase compositions of the samples obtained and waste elements partitioning among co-existing phases were investigated in detail using powder X-ray diffraction, scanning electron microscopy with energy dispersive spectroscopy, and transmission electron microscopy. Cerium enters cerianite-based solid solution, lucasite (if present), and to a lesser extent, pyrochlore and zirconolite. Europium and gadolinium enter predominantly zirconolite and pyrochlore. The highest uranium concentrations were found in a uraninite-based cubic solid solution or pyrochlore and zirconolite.

Carbothermal reduction of low-grade pyrolusite by microwave heating

RSC Advances ◽  
2014 ◽  
Vol 4 (102) ◽  
pp. 58164-58170 ◽  
Author(s):  
Qianxu Ye ◽  
Hongbo Zhu ◽  
Libo Zhang ◽  
Peng Liu ◽  
Guo Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Crystal Structures ◽  
Microwave Heating ◽  
Energy Dispersive Spectroscopy ◽  
Carbothermal Reduction ◽  
Low Grade ◽  
X Ray Diffraction ◽  
X Ray ◽  
Scanning Electron

Pyrolusite was carbothermally reduced using coal by microwave heating, and the crystal structures and microstructures of the samples were characterized after microwave heating using X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive spectroscopy (EDS).

Isothermal Sections of the U-Fe-Sb Ternary System

2012 ◽  
Vol 194 ◽  
pp. 21-25 ◽  
Author(s):  
Margarida S. Henriques ◽  
Thomas Malnoe ◽  
Olivier Tougait ◽  
Rui Vilar ◽  
Antonio Pereira Gonçalves
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Solid Solution ◽  
Scanning Electron Microscopy ◽  
Ternary Phase ◽  
Energy Dispersive Spectrometry ◽  
X Ray Diffraction ◽  
Isothermal Sections ◽  
X Ray ◽  
Scanning Electron

A systematic study on the ternary uranium-iron-antimony was made at 700 and 750°C through powder X-ray diffraction and Scanning Electron Microscopy coupled with Energy Dispersive Spectrometry. The assessed sections confirmed the existence and crystal structure of the binary intermetallic compounds as well as the ternary phase UFeSb2. Moreover it was found that UFeSb2 is part of a solid solution, UFe1-xSb2, stable for 193Fe3-xSb4, crystallizing in the cubic type Y3Au3Sb4 and stable for 22

Sign in / Sign up

Export Citation Format

Share Document