scholarly journals Nanoporous Anodic Aluminum-Iron Oxide with a Tunable Band Gap Formed on the FeAl3 Intermetallic Phase

Materials ◽  
2020 ◽  
Vol 13 (16) ◽  
pp. 3471 ◽  
Author(s):  
Paulina Chilimoniuk ◽  
Robert P. Socha ◽  
Tomasz Czujko

Nanostructured anodic oxide layers on an FeAl3 intermetallic alloy was prepared by two-step anodization in 20 wt.% H2SO4 at 0 °C. The obtained anodic oxide coating was subjected to phase and chemical composition analysis using XPS and XRD techniques. An analysis of the band gap of individual coatings was also performed. The applied parameters of the anodization process were determined, enabling the formation of a nanostructured coating on the FeAl3 intermetallic alloy. Tests were carried out on samples produced at a voltage between 10 V and 22.5 V in 2.5 V steps. The produced coatings were subjected to an annealing process at 900 °C for 2 h in an argon protective atmosphere. Moreover, the influence of the substrate chemical composition on the chemical and phase composition of the anodic oxide are discussed. Band gaps of 2.37 eV at 22.5 V and 2.64 eV at 10 V were obtained directly after the anodizing process. After applying the heat treatment, band gap values of 2.10 eV at 22.5 Vand 2.48 eV for the coating produced at 10 V were obtained.

2008 ◽  
Vol 595-598 ◽  
pp. 763-768
Author(s):  
Martah Homa ◽  
Zbigniew Żurek

The high temperature corrosion behavior of Fe20Cr6Al-Y,Hf steel was studied in the range of temperature 800-1000oC in H2/H2S atmospheres at pS2=10-2 ,10-3 and 10-4 Pa sulphur vapor pressures. Kinetics depend on the temperature and sulphur vapor pressure. After 24 hours the whole specimen was practically consumed because the samples were 0,06 cm thick. Morphology of the scales have been performed by SEM techniques. Phase and chemical composition have been studied by EDX and XRD techniques. It was found that scale formed on Fe20Cr6Al-Y,Hf alloy was built with porosity sulphides layer. EDX analysis of the scale surface show that the any aluminum, hafnium and yttrium sulfides were found in the formed scale layer, however small amounts of Al2S3 was detected in scale/steel interface. Also internal sulphidation was observed. A phase analysis of the formed scale revealed that it is composed mainly of an FeS, Fe7S8 phases and CrS, Cr5S6. Result were compared with data obtained on the pure Fe and Cr samples.


Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 379
Author(s):  
Da Qing Yu ◽  
Xiao Jing Han ◽  
Ting Yu Shan ◽  
Rui Xu ◽  
Jin Hu ◽  
...  

The authors would like to correct an error in the title paper [...]


2021 ◽  
Vol 156 ◽  
pp. 105112
Author(s):  
Samin Fathalinejad ◽  
Esben Taarning ◽  
Peter Christensen ◽  
Jan H. Christensen

2010 ◽  
Vol 158 ◽  
pp. 197-203 ◽  
Author(s):  
Jie Liu ◽  
Yue Xin Han ◽  
Wan Zhong Yin

The process mineralogy of potassium-rich shale from Chaoyang of Liaoning, China, was studied. Research results showed there are much less variety and smaller quantities in mineral compositions. Calculated mineral composition by means of chemical composition analysis combined with XRD, MLA, IR and TG-DSC analyses showed that main minerals with were Potassium-feldspar, muscovite, biotite and illite, and gangue minerals were quartz and small amounts of hematite. Potassium-rich minerals such as potassium-feldspar and muscovite contact smoothly with quartz respectively, and there was the direction arrangement among potassium-feldspar, quartz and muscovite in the shale. And quartz and hematite were main cement in the shale. The influences of the research results on the potassium extraction from potassium-rich shale were distinct.


2011 ◽  
Vol 383-390 ◽  
pp. 7613-7618
Author(s):  
Y. Yang ◽  
F. Yu ◽  
Ping Han ◽  
R.P. Ge ◽  
L. Yu

Capacitance-voltage method was used to analyze composition of the Si1-xGex alloy films with a stochiometry gradient of Ge, which were epitaxially grown on Si (100) substrate by chemical vapor deposition. Using the capacitance characteristics of Si1-xGex/Si obtained by applying a reserve bias to the Hg electrode probe, the contact barrier height for Hg/Si1-xGexjunction and Si1-xGex/Si junction, and band gap of SSi1-xGex were estimated respectively. With the band gap of Si1-xGex, composition of Si1-xGex in Hg/Si1-xGex junction and Si1-xGex/Si junction were further obtained. Because analyzed Si1-xGex was formed through bilateral inter-diffusion of Si into the epilayer and Ge into the substrate during the deposition, Ge distribution from surface to substrate in Si1-xGex alloy films can be figured out by fitting to diffusion exponential function. The Ge distribution acquired this way was in accordance with the depth profile by auger electron spectrum.


2020 ◽  
Author(s):  
Huimin Xu ◽  
Yuanyuan Zhao ◽  
Yuanzhen Suo ◽  
Yayu Guo ◽  
Yi Man ◽  
...  

Abstract Background: Cell wall imaging can considerably permit direct visualization of the molecular architecture of cell walls and provide the detailed chemical information on wall polymers, which is imperative to better exploit and use the biomass polymers; however, detailed imaging and quantifying of the native composition and architecture in the cell wall remains challenging.Results: Here, we describe a label-free imaging technology, coherent Raman scattering microscopy (CRS), including coherent anti-Stokes Raman scattering (CARS) microscopy and stimulated Raman scattering (SRS) microscopy, which images the major structures and chemical composition of plant cell walls. The major steps of the procedure are demonstrated, including sample preparation, setting the mapping parameters, analysis of spectral data, and image generation. Applying this rapid approach, which will help researchers understand the highly heterogeneous structures and organization of plant cell walls.Conclusions: This method can potentially be incorporated into label-free microanalyses of plant cell wall chemical composition based on the in situ vibrations of molecules.


2019 ◽  
Vol 91 (2) ◽  
Author(s):  
Paweł Widomski ◽  
Zbigniew Gronostajski ◽  
Marcin Kaszuba ◽  
Jagoda Kowalska ◽  
Mariusz Pawełczyk

In response to the growing need to use wear-resistant layers that increase durability of tools in forging pro-cesses, hybrid layers have been proposed that combine hardfacing with nitriding treatment. This article presents the results of laboratory tests of surface wear-resistant layers made with a new hybrid technology Gas-Shielded Metal Arc surfacing (hardfacing) with ZeroFlow gas nitriding. Specimens made with hardfacing or nitriding were prepared and examined. Analysis covered the thorough microstructure study, EDX chemical composition analysis and microhardness analysis. In experiment, 3 different types of nitrided layers were proposed for alpha, gamma prim and epsilon nitrides in the surface layer. The results of metallographic research in the surface layer was presented. The analysis of chemical composition in the particular overlay welds was performed to determine the content of alloying elements in the particular overlay welds. The susceptibility to nitriding of used weld materials as well as the ability to form particular types of nitrides on selected welded substrates was also tested.


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