Xps and Xrd Studies of Uranium Rich Minerals from Cigar Lake, Saskatchewan

1987 ◽  
Vol 112 ◽  
Author(s):  
S. Sunder ◽  
P. Taylor ◽  
J. J. Cramer
Keyword(s):  
Nuclear Fuel ◽  
Photoelectron Spectroscopy ◽  
Uranium Concentration ◽  
Management Program ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Used Nuclear Fuel ◽  
Nuclear Fuel Waste ◽  
Lake Deposits

AbstractSamples of uranium ore from the 1,300 million year old Cigar Lake deposits in northern Saskatchewan have been investigated using X ray Photoelectron Spectroscopy (XPS) and X ray Diffraction (XRD). The XPS spectra showed the peaks for U, Pb, 0, C, Si, Ca and Mg. Analysis of highresolution XPS spectra showed that the oxidation state of uranium in these minerals is equal to, or lower than, that of U3O7. The XRD data confirm the presence of an oxidized phase, most likely α U3O7., in addition to UO2. The low U(VI)/U(IV) ratio in these minerals is consistent with the low uranium concentration found in groundwater in contact with these uranium minerals. The relevance of these results to the disposal concept of used nuclear fuel in the Canadian Nuclear Fuel Waste Management Program is discussed.

scholarly journals Optical, XPS and XRD Studies of Semiconducting Copper Sulfide Layers on a Polyamide Film

2009 ◽  
Vol 2009 ◽  
pp. 1-8 ◽  
Author(s):  
Valentina Krylova ◽  
Mindaugas Andrulevičius
Keyword(s):  
Photoelectron Spectroscopy ◽  
Copper Sulfide ◽  
Diffusion Method ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Xrd Studies ◽  
Polyamide Film ◽  
Indirect Band Gap ◽  
Xrd Method

Copper sulfide layers were formed on polyamide PA 6 surface using the sorption-diffusion method. Polymer samples were immersed for 4 and 5 h in 0.15 mol⋅  solutions and acidified with HCl (0.1 mol⋅) at . After washing and drying, the samples were treated with Cu(I) salt solution. The samples were studied by UV/VIS, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) methods. All methods confirmed that on the surface of the polyamide film a layer of copper sulfide was formed. The copper sulfide layers are indirect band-gap semiconductors. The values of are 1.25 and 1.3 eV for 4 h and 5 h sulfured PA 6 respectively. Copper XPS spectra analyses showed Cu(I) bonds only in deeper layers of the formed film, while in sulfur XPS S 2p spectra dominating sulfide bonds were found after cleaning the surface with ions. It has been established by the XRD method that, beside , the layer contains as well. For PA 6 initially sulfured 4 h, grain size forchalcocite, , was  nm and fordjurleite, , it was 54.17 nm. The sheet resistance of the obtained layer varies from 6300 to 102 .

Surface Characterization of Carbon-Bearing Magnetite (CBM) and Carbon-Bearing Ni(II)-Ferrite (CBNF)

1994 ◽  
Vol 344 ◽  
Author(s):  
T. Sano ◽  
K. Akanuma ◽  
M. Tsuji ◽  
Y. Tamaura
Keyword(s):  
Photoelectron Spectroscopy ◽  
Spinel Structure ◽  
Surface Characterization ◽  
Carbon Deposition ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Oxygen Ions ◽  
Diffraction Patterns

AbstractOxygen-deficient magnetite (ODM; Fe3O4-δ, δ>0) synthesized by reduction of magnetite with H2 at 300°C decomposed CO2 to carbon with an efficiency of nearly 100% at 300°C. In this reaction, two oxygen ions of the CO2 were incorporated into the spinel structure of ODM and carbon was deposited on the surface of ODM with zero valence to form visible particles. The particles of carbon separated from ODM were studied by Raman, energy-dispersive X-ray and wave-dispersive X-ray spectroscopies. The carbon which had been deposited on the ODM was found to be a mixture of graphite and amorphous carbon in at least two levels of crystallization. X-ray photoelectron spectroscopy and X-ray diffraction patterns of the carbon-bearing magnetite (CBM) showed no indication of carbide (Fe3C) or metallic iron (α-Fe) phase formation. In the C 1s XPS spectra of the CBM, no peaks were observed which could be assigned to CO2 or CO. X-ray diffractometry, chemical analysis and TG-MS measurement showed that the carbon-bearing Ni(II)-ferrite (CBNF) (Ni(II)/Fetotal = 0.15) synthesized by the carbon deposition reaction from CO2 with the H2-reduced Ni(II)-ferrite was represented by (Ni0.28Fe2.72O4.00)1-δ (Ni2+06.9Fe2+2.31O3.00)δCτ (δ= 0.27, τ= 0.17). The carbon of the CBNF gave the CIOlayer-like oxide containing some Ni2+ ions.

Study Behavior of XPS Spectra of Ni, Mn, Y and O in Y2NiMnO6 Ceramics

2015 ◽  
Vol 804 ◽  
pp. 97-103 ◽  
Author(s):  
Panakamon Deeyai ◽  
Thanapong Sareein ◽  
Bundit Putasaeng ◽  
Naphat Chathirat
Keyword(s):  
Photoelectron Spectroscopy ◽  
Ceramic Materials ◽  
Effect Of Temperature ◽  
Decomposition Technique ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Study Behavior ◽  
Sintering Time ◽  
Effects Of Temperature

Bulk Y2NiMnO6 samples were prepared by thermal decomposition technique at 800 °C for 6 hours. The effects of temperature on the structure of ceramics were investigated for different sintering temperatures in the range of 1000-1300 °C, while kept constant the sintering time of 12 hours. Structural characterization had been investigated via X-ray diffraction (XRD) on samples of different sintering temperatures. Results from the experiment had revealed that high temperature affected oxide in ceramic materials. Further analysis with X-ray photoelectron spectroscopy (XPS) technique had revealed an outstanding point of ceramics by investigating the Ni 2p, 2p3/2, Mn 2p1/2, 2p3/2, and Y 3d3/2, 3d5/2 at the surface of Y2NiMnO6 ceramics. The changes in relative intensity of XPS peaks and the shifts in their binding energy (eV) were observed in the results, while the effect of temperature on oxide in ceramics may be investigated with dielectric property in the future.

Predicted Behavior of Technetium in a Geological Disposal Vault For Used Nuclear Fuel - Ramifications of a Recent Determination of the Enthalpy of Formation of TcO2(cr)

1995 ◽  
Vol 412 ◽  
Author(s):  
R. J. Lemire ◽  
D. J. Jobe
Keyword(s):  
Nuclear Fuel ◽  
Management Program ◽  
Heat Of Solution ◽  
Used Nuclear Fuel ◽  
A Value ◽  
Reducing Conditions ◽  
Congruent Dissolution ◽  
Nuclear Fuel Waste ◽  
The Enthalpy Of Formation

AbstractRecently, we reported a value of ΔH°(TcO2(cr)) = -(458 ± 6) kJ·mol-1based on heat of solution measurements. The implications of this value on the database used in the Canadian Nuclear Fuel Waste Management Program for the evaluation of the technetium released by congruent dissolution of used UO2 fuel have now been assessed.It is probable that the Tc(IV) oxides are more stable than previously predicted and, hence, they are less likely to be oxidized to TcO4(aq) under moderately reducing conditions. We have revised earlier calculations done to predict the solution concentrations of technetium species in a vault as a function of the oxidation conditions in model groundwaters.

Fe-loaded zeolites as catalysts in the formation of humic substance-like darkcoloured polymers in polycondensation reactions of humic precursors

Clay Minerals ◽  
2012 ◽  
Vol 47 (3) ◽  
pp. 355-364 ◽  
Author(s):  
S. Fukuchi ◽  
M. Fukushima ◽  
R. Nishimoto ◽  
G. Qi ◽  
T. Sato
Keyword(s):  
Cation Exchange ◽  
Photoelectron Spectroscopy ◽  
Ionic Species ◽  
Exchange Capacity ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Catalytic Activities ◽  
Ion Exchange Reaction ◽  
Xrd Patterns

AbstractTo enhance the catalytic activities of zeolites for the polycondensation reactions of humic precursors, Fe was loaded into a zeolite via an ion-exchange reaction and the resulting product was subjected to calcination at 773 K. Two types iron-loaded zeolites were prepared using one equivalent (Fe-Z-1) and 10-equivalents (Fe-Z-10) of Fe2+ to the cation-exchange capacity of a natural zeolite from Niki town (Hokkaido, Japan). X-ray diffraction (XRD) patterns and X-ray photoelectron spectroscopy (XPS) spectra showed that the Fe(II) that was originally loaded into the cation-exchange sites in the zeolite became oxidized to a Fe(III) ionic species during the preparation. The catalytic activities of each zeolite were evaluated, based on the degree of darkening for reaction mixtures containing catechol, glycine and glucose as model humic precursors. The catalytic activities of Fe-Z-1 and Fe-Z-10 were higher than that for an untreated zeolite, and increased with the amount of Fe in the zeolite.

Prediction of the Oxidative Dissolution Rates of Used Nuclear Fuel in a Geological Disposal Vault Due to the Alpha Radiolysis of Water

1994 ◽  
Vol 353 ◽  
Author(s):  
S. Sunder ◽  
D.W. Shoesmith ◽  
N.H. Miller
Keyword(s):  
Nuclear Fuel ◽  
Management Program ◽  
Oxidative Dissolution ◽  
Dissolution Rates ◽  
Used Nuclear Fuel ◽  
A Value ◽  
Thin Layer Cell ◽  
Alpha Radiolysis ◽  
Nuclear Fuel Waste ◽  
Electrochemical Model

AbstractEffects of alpha radiolysis of water on the corrosion of nuclear fuel (UO2) have been investigated in solutions at pH = 9.5, i.e., a value close to that expected in groundwaters at the depth of the disposal vault proposed in the Canadian nuclear fuel waste management program, CNFWMP. The corrosion potentials of UO2 electrodes exposed to the products of alpha radiolysis of water were monitored as a function of alpha flux and exposure time in a specially designed thin-layer cell. The oxidative dissolution rates of UO2 are calculated from the steady-state values of the corrosion potential using an electrochemical model. A procedure to predict the dissolution rate of used nuclear fuel in groundwater as a function of fuel cooling time is described, and illustrated by calculating the dissolution rates for the reference used fuel in the CNFWMP (Bruce CANDU reactor fuel, burnup 685 GJ/kg U). It is shown that the oxidative dissolution of used fuel in the CNFWMP will be important only for time periods ≤ 600 a at this burnup and assuming no decrease in pH.

scholarly journals Calcined Co(II)-Triethylenetetramine, Co(II)- Polyaniline-Thiourea as the Cathode Catalyst of Proton Exchanged Membrane Fuel Cell

Polymers ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3070
Author(s):  
Wen-Yao Huang ◽  
Li-Cheng Jheng ◽  
Tar-Hwa Hsieh ◽  
Ko-Shan Ho ◽  
Yen-Zen Wang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Linear Sweep Voltammetry ◽  
Conducting Medium ◽  
Membrane Electrode ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Co Catalysts ◽  
Electrode Assemblies ◽  
Diffraction Patterns

Triethylenetetramine (TETA) and thiourea complexed Cobalt(II) (Co(II)) ions are used as cathode catalysts for proton exchanged membrane fuel cells (PEMFCs) under the protection of polyaniline (PANI) which can become a conducting medium after calcination. Fourier-transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) spectra clearly reveal the presence of typical carbon nitride and sulfide bonds of the calcined Nitrogen (N)- or Sulfur (S)-doped co-catalysts. Clear (002) and (100) planes of carbon-related X-ray diffraction patterns are found for co-catalysts after calcination, related to the formation of a conducting medium after the calcination of PANI. An increasing intensity ratio of the D to G band of the Raman spectra reveal the doping of N and S elements. More porous surfaces of co-catalysts are found in scanning electronic microscopy (SEM) micropictures when prepared in the presence of both TETA and thiourea (CoNxSyC). Linear sweep voltammetry (LSV) curves show the highest reducing current to be 4 mAcm−2 at 1600 rpm for CoNxSyC, indicating the necessity for both N- and S-doping. The membrane electrode assemblies (MEA) prepared with the cathode made of CoNxSyC produces the highest maximum power density, close to 180 mW cm−2.

X-RAY Photoelectron Spectroscopic Study of Cigar Lake Uranium Ore: A Natural Analog for Used Fuel

1991 ◽  
Vol 257 ◽  
Author(s):  
S. Sunder ◽  
J.J. Cramer ◽  
N.H. Miller
Keyword(s):  
High Resolution ◽  
Organic Carbon ◽  
Photoelectron Spectroscopy ◽  
Uranium Deposit ◽  
Radioactive Decay ◽  
Xps Spectra ◽  
X Ray ◽  
Natural Analog ◽  
Cutting Processes ◽  
Nuclear Fuel Waste

ABSTRACTX-ray photoelectron spectroscopy (XPS) was used to study samples from the Cigar Lake uranium deposit in northern Saskatchewan. Two uranium-rich sections, CS-615 and CS-620 were studied. Peaks due to U, 0, C, Pb, Si, Ca, Al, S, Cu and Th were seen in the XPS spectra. Concentrations of Pb of up to 14 wt% were measured by XPS and correspond to the Pb ingrowth by radioactive decay during the 1.3 billion years since the ore was formed. High-resolution spectra were recorded for the U, Pb, 0, and C bands. Lead was in the +2 oxidation state in all samples. The carbon signal indicated the presence of organic carbon, while the oxygen bands indicated the presence of significant amounts of water in the samples. The samples from the CS-615 section had U6+/U4+ ratios between 0.16 and 0.29. However, the U6+/U4+ ratios for section CS-620 were about 0.7 but this is attributed to oxidation of the ore by water during the drilling and cutting processes. The significance of the results for disposal concepts in nuclear fuel waste management programs is discussed.

scholarly journals Synthesis of Uniformly Sized Bi0.5Sb1.5Te3.0 Nanoparticles via Mechanochemical Process and Wet-Milling for Reduced Thermal Conductivity

Materials ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 536
Author(s):  
Bo-In Park ◽  
Miri Shin ◽  
Jaeho Park ◽  
Jae-Seung Lee ◽  
Seung Yong Lee ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Milling Process ◽  
Wet Milling ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
Mechanochemical Process ◽  
Plasma Sintering ◽  
Transmission Electron ◽  
Spark Plasma

In this study, Bi0.5Sb1.5Te3.0 (BST) nanoparticles (NPs) with high crystallinities were synthesized via a mechanochemical process (MCP). X-ray diffraction (XRD), and Raman and X-ray photoelectron spectroscopy (XPS) spectra of the BST NPs showed that the Bi, Sb, and Te powders successfully formed BiSbTe phase and transmission electron microscopy (TEM) images, verifying the high crystallinity and smaller size, albeit agglomerated. The as-synthesized BST NPs with agglomerated clusters were ground into smaller sizes of approximately 41.8 nm with uniform distribution through a simple wet-milling process during 7 days. The thermal conduction behaviors of bulk alloys fabricated by spark plasma sintering (SPS) of the BST NPs were studied by comparing those of samples fabricated from as-synthesized BST NPs and a BST ingot. The thermal conductivities (κ) of the BST nanocomposites were significantly reduced by introducing BST NPs with smaller grain sizes and finer distributions in the temperature range from 300 to 500 K. The BST nanocomposites fabricated from wet-milled BST NPs offered ultralow κ values of 0.84 W m−1 K−1 at approximately 398 K.

Chemical and Mineralogical Characterizations of Cobalt Precursor Recovered from Spent Lithium-Ion Batteries with Incineration Process

2014 ◽  
Vol 878 ◽  
pp. 51-56
Author(s):  
Tao Zhang ◽  
Ya Qun He ◽  
Lin Han Ge ◽  
Hong Li ◽  
Shan Wu
Keyword(s):  
Thermal Treatment ◽  
Lithium Ion Batteries ◽  
Photoelectron Spectroscopy ◽  
Lithium Ion ◽  
Chemical State ◽  
X Ray Diffraction ◽  
Xps Spectra ◽  
X Ray ◽  
State Changes ◽  
Incineration Process

The chemical and mineralogical characterizations of cobalt precursor recovered from spent lithium-ion batteries with incineration process was analyzed by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). It indicates that Co exists in the form of LiCoO2. However, after thermal treatment, complex products including LiCoO2, Co3O4, and Co2AlO4 etc. generated, in which Co3O4 has strong signal. The XPS spectra shows that Li(1-x)CoO2 and LiCoO2 are the main chemical state of Co in the original sample, but after thermal treatment, the chemical state changes to Co3O4. Besides, there are undecomposed Li(1-x)CoO2, CoF3 and Co. Analyses indicate that Co is enriched after thermal treatment and chemical state of some Co have been certified.

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