High Purity Magnetite Microparticles Directly Derived from Mill Scale via Hydrogen-Reduction Method

2021 ◽  
Vol 1016 ◽  
pp. 286-291
Author(s):  
Autchariya Boontanom ◽  
Piyada Suwanpinij
Keyword(s):  
Flow Rate ◽  
High Purity ◽  
Gas Flow ◽  
Reduction Method ◽  
Hydrogen Reduction ◽  
Reduction Temperature ◽  
Mixed Gas ◽  
Mill Scale ◽  
X Ray ◽  
Ar Gas

This study develops a fast and simple way to produce high purity magnetite (Fe3O4) microparticles from mill scale by using hydrogen reduction with the addition of vapour as a retarding agent. By optimising the reduction temperature and gas flow rate, the characterisations by X-ray diffractometry technique shown that the Fe3O4 fraction of over 93 wt.-% is shown at the reduction temperature of 550 – 650 oC with the flow rate of the 4.5-5.5 mol%H2 + Ar gas + H2O gas mixture from 100 – 200 ml/min. The highest Fe3O4 fraction of over 99 wt.-% can be achieved from the reduction with the mixed gas at 650 oC and the flow rate of 200 ml/min for 4 hour.

scholarly journals Experimental Analysis and Characterization of High-Purity Aluminum Nanoparticles (Al-NPs) by Electromagnetic Levitation Gas Condensation (ELGC)

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2084
Author(s):  
Rana Sabouni Tabari ◽  
Mohammad Halali ◽  
Akbar A. Javadi ◽  
Mohammad Hassan Khanjanpour
Keyword(s):  
Particle Size ◽  
Flow Rate ◽  
High Purity ◽  
Gas Flow ◽  
Electromagnetic Levitation ◽  
Aluminum Nanoparticles ◽  
Gas Flow Rate ◽  
X Ray ◽  
Gas Condensation ◽  
High Purity Aluminum

The production of high-purity aluminum nanoparticles (Al-NPs) is challenging due to the highly reactive nature of Al metals. Electromagnetic levitation gas condensation (ELGC) is a promising method to produce high-purity metallic particles as it avoids the interaction between molten metal and refractory-lined, which guarantees the removal of impurities such as oxygen (O). In this research, high-purity Al-NPs were successfully fabricated via ELGC process and fully characterized. The effects of power input and gas flow rate on particle size and distribution were analyzed using field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), and dynamic light scattering (DLS). The results showed that the Al-NPs have spherical morphologies with an average diameter of 17 nm and size distribution of NPs is narrow under helium (He) flow rate of 15 L/min at a constant temperature of 1683 ± 10 K. The purity of the NPs was confirmed by utilizing X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), and X-ray fluorescence (XRF). Finally, metal purity of 99.976% and 99.97% was measured by AAS and XRF analyses, respectively. Moreover, it was found that increasing gas flow rate and sample temperature results in a decrease in the particle size. The particle sizes for the Al-NPs obtained under He atmosphere were smaller than those obtained under Ar atmosphere.

Gan Nanowire Growth by Thermal Evaporation Method

2012 ◽  
Vol 501 ◽  
pp. 276-280
Author(s):  
Leila Shekari ◽  
Abu Hassan Haslan ◽  
Hassan Zainuriah
Keyword(s):  
Gas Flow ◽  
Thermal Evaporation ◽  
Mixed Gas ◽  
Thermal Evaporation Method ◽  
X Ray ◽  
Transmission Electron ◽  
Gas Atmosphere ◽  
Ar Gas ◽  
Uniform Diameter ◽  
Different Diameters

In this research we introduce an inexpensive method to produce highly crystalline GaN Nanowires (NWs) grown on porous zinc oxide (PZnO) using commercial GaN powder, either in argon gas or combination of nitrogen and Ar gas atmosphere, by thermal evaporation. Morphological structural studies using transmission electron microscope (TEM) and scanning electron microscopy (SEM) measurements showed the role of porosity and different gas flowing, in the alignment and nucleation of these NWs. The NWs grown under flow of mix gases have very different diameters of between 50 and 200 nm, but those which were grown in Ar gas atmosphere, have rather uniform diameter of around 50 nm. The length of the GaN NWs was uniform, (around 10 µm). Optical and structural characterizations were performed by energy-dispersive X-ray spectroscopy (EDX) and high resolution X-ray diffraction (HR-XRD). Results revealed that these NWs are of single-crystal hexagonal GaN with [oooı] and [ıoīı] growth directions for the NWs grown under Ar and mixed gas flow.

Electron Microscopy/Diffraction Study of the Ternary Mn-Er-S System

1990 ◽  
Vol 48 (1) ◽  
pp. 76-77
Author(s):  
A. R. Landa Canovas ◽  
L.C. Otero Diaz ◽  
T. White ◽  
B.G. Hyde
Keyword(s):  
Electron Microscopy ◽  
Gas Flow ◽  
Graphite Crucible ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Alumina Crucible ◽  
X Ray ◽  
Intermediate Phases ◽  
Twin Band ◽  
Ar Gas

X-Ray diffraction revealed two intermediate phases in the system MnS+Er2S3,:MnEr2S4= MnS.Er2S3, and MnEr4S7= MnS.2Er2S3. Their structures may be described as NaCl type, chemically twinned at the unit cell level, and isostructural with CaTi2O4, and Y5S7 respectively; i.e. {l13} NaCl twin band widths are (4,4) and (4,3).The present study was to search for structurally-related (twinned B.) structures and or possible disorder, using the more sensitive and appropiate technigue of electron microscopy/diffraction.A sample with nominal composition MnEr2S4 was made by heating Mn3O4 and Er2O3 in a graphite crucible and a 5% H2S in Ar gas flow at 1500°C for 4 hours. A small amount of this material was thenannealed, in an alumina crucible, contained in sealed evacuated silica tube, for 24 days at 1100°C. Both samples were studied by X-ray powder diffraction, and in JEOL 2000 FX and 4000 EX microscopes.

A Study on the Effect of Process Parameters on Surface Topography of Al Thin Films on Various Substrates Using AFM

2011 ◽  
Vol 383-390 ◽  
pp. 903-908
Author(s):  
S. Shanmugan ◽  
D. Mutharasu ◽  
Z. Hassan ◽  
H. Abu. Hassan
Keyword(s):  
Thin Films ◽  
Surface Topography ◽  
Flow Rate ◽  
Gas Flow ◽  
Process Conditions ◽  
Gas Flow Rate ◽  
Glass Substrates ◽  
Sputtering Power ◽  
Large Particles ◽  
Ar Gas

Al thin films were prepared over different substrates at various process conditions using DC sputtering. The surface topography of all prepared films was examined using AFM technique. Very smooth, uniform and dense surface were observed for Al films coated over Glass substrates. The observed particle size was nano scale (20 -70 nm) for Glass substrates. Sputtering power showed immense effect on surface roughness with respective to Ar gas flow rate. Noticeable change on surface with large particles was observed in Copper substrates at various sputtering power and gas flow rate.

scholarly journals Carbon Co-Deposition During Gas Reduction of Water-Atomized Fe-Cr-Mo Powder

2017 ◽  
Vol 62 (2) ◽  
pp. 1119-1124
Author(s):  
B. Ali ◽  
S.H. Choi ◽  
S.J. Seo ◽  
D.Y. Maeng ◽  
C.G. Lee ◽  
...  
Keyword(s):  
Carbon Content ◽  
Oxide Layer ◽  
Iron Powder ◽  
Flow Rate ◽  
Gas Flow ◽  
Gas Flow Rate ◽  
High Quality ◽  
Exponential Relationship ◽  
Water Atomization ◽  
Ar Gas

AbstractThe water atomization of iron powder with a composition of Fe-3Cr-0.5Mo (wt.%) at 1600°C and 150 bar creates an oxide layer, which in this study was reduced using a mixture of methane (CH4) and argon (Ar) gas. The lowest oxygen content was achieved with a 100 cc/min flow rate of CH4, but this also resulted in a co-deposition of carbon due to the cracking of CH4. This carbon can be used directly to create high-quality, sinter hardenable steel, thereby eliminating the need for an additional mixing step prior to sintering. An exponential relationship was found to exist between the CH4gas flow rate and carbon content of the powder, meaning that its composition can be easily controlled to suit a variety of different applications.

scholarly journals Structural and X-Ray Photoelectron Spectroscopy Study of Al-Doped Zinc-Oxide Thin Films

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Bong Ju Lee ◽  
Ho Jun Song ◽  
Jin Jeong
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Flow Rate ◽  
Photoelectron Spectroscopy ◽  
Gas Flow ◽  
Rf Magnetron Sputtering ◽  
Photoelectron Spectra ◽  
Gas Flow Rate ◽  
X Ray ◽  
Oxide Component

Al-doped zinc-oxide (AZO) thin films were prepared by RF magnetron sputtering at different oxygen partial pressures and substrate temperatures. The charge-carrier concentrations in the films decreased from 1.69 × 1021to 6.16 × 1017 cm−3with increased gas flow rate from 7 to 21 sccm. The X-ray diffraction (XRD) patterns show that the (002)/(103) peak-intensity ratio decreased as the gas flow rate increased, which was related to the increase of AZO thin film disorder. X-ray photoelectron spectra (XPS) of the O1s were decomposed into metal oxide component (peak A) and the adsorbed molecular oxygen on thin films (peak B). The area ratio of XPS peaks (A/B) was clearly related to the stoichiometry of AZO films; that is, the higher value of A/B showed the higher stoichiometric properties.

scholarly journals ZnO:Al Thin Films with Buffer Layers Fabricated via Nitrogen Mediated Crystallization: Effects of N2/Ar Gas Flow Rate Ratio

2012 ◽  
Vol 37 (2) ◽  
pp. 165-168 ◽  
Author(s):  
Iping Suhariadi ◽  
Naho Itagaki ◽  
Kazunari Kuwahara ◽  
Koichi Oshikawa ◽  
Daisuke Yamashita ◽  
...  
Keyword(s):  
Thin Films ◽  
Flow Rate ◽  
Rate Ratio ◽  
Gas Flow ◽  
Buffer Layers ◽  
Flow Rate Ratio ◽  
Gas Flow Rate ◽  
Ar Gas

scholarly journals Montmorillonite immobilized Fe/Ni bimetallic prepared by dry in-situ hydrogen reduction for the degradation of 4-Chlorophenlo

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Shuo-Shuo Zhang ◽  
Ning Yang ◽  
Xuming Zhuang ◽  
Liying Ren ◽  
Vinothkumar Natarajan ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Bimetallic Nanoparticles ◽  
Hydrogen Reduction ◽  
Maximum Activity ◽  
Synthesis Process ◽  
Reduction Temperature ◽  
Liquid Environment ◽  
X Ray ◽  
Ni Content

Abstract This study puts forward a new way to produce montmorillonite immobilized bimetallic nickel-iron nanoparticles by dry in-situ hydrogen reduction method in the non-liquid environment, which effectively inhibits the oxidation of iron and nickel during the synthesis process and improves the reactivity of the material. The degradation of 4-Chlorophenol (4-CP) was investigated to examine the catalytic activity of the material. The morphology and crystal properties of the montmorillonite-templated Fe/Ni bimetallic particles were explored by using scanning electron microscopy, transmission electron microscopy, X-ray diffraction studies, and energy dispersive X-ray spectroscopy analysis. Results suggest that Fe and Ni particles were homogeneously dispersed on the montmorillonite. The optimization of Ni content and reduction temperature over the degradation of 4-CP was also studied. The introduction of Ni intensely improved the degradation of 4-CP and reached over 90% when Ni content was 28.5%. The degradation rate increased significantly with the increase of reduction temperature and showed maximum activity at the reduction tempreature of 800 °C. This study offers a new method to fabricate montmorillonite immobilized Fe/Ni bimetallic nanoparticles in the non-liquid environment and the composites exhibited high degradation activity to chlorinated organic compounds.

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