Characterisation of concrete, mortar and calcium silicate hydrated phases (CSH) and thorium retention analyses by ion beam techniques.

2012 ◽  
Vol 1475 ◽  
Author(s):  
Ursula Alonso ◽  
Tiziana Missana ◽  
Miguel Garcia-Gutierrez ◽  
Henar Rojo ◽  
Alessandro Patelli ◽  
...  
Keyword(s):  
Calcium Silicate ◽  
Cement Hydration ◽  
Ion Beam ◽  
X Ray ◽  
Tetravalent Actinide ◽  
Radioactive Waste Repositories ◽  
Edx Analyses ◽  
Waste Repositories ◽  
Beam Technique

ABSTRACTCement-based materials, like concrete and mortar, are widely used in radioactive waste repositories. A deep characterization of these heterogeneous materials, and of their main phases, is necessary to evaluate their capability of retaining critical radionuclides (RN).In this study, the ion beam technique micro- Particle Induced X- Ray Emission (μPIXE) is used to characterize the concrete and mortar used in the Spanish low level waste repository. Two calcium silicate hydrate (CSH) phases with different Ca/Si ratio are also studied, because they are known to be amongst the most relevant phases, formed upon cement hydration, that retain RN. The retention of thorium on the above mention materials, as relevant tetravalent actinide, is also analyzed. Results are compared with Scanning Electron Microscopy- Energy Dispersive X-Ray Spectroscopy (SEM-EDX) analyses.

RBS and micro-PIXE study of I and Cs Heterogeneous Retention on Concrete

2008 ◽  
Vol 1124 ◽  
Author(s):  
Ursula Alonso ◽  
Tiziana Missana ◽  
Miguel García-Gutiérrez ◽  
Alessandro Patelli ◽  
Daniele Ceccato ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Rutherford Backscattering Spectrometry ◽  
Ion Beam ◽  
Sorption Behaviour ◽  
X Ray ◽  
Cement Based Materials ◽  
Radioactive Waste Repositories ◽  
Waste Repositories ◽  
Low Level Radioactive Waste ◽  
Diffusion Profiles

AbstractA combination of two nuclear ion beam techniques, Rutherford Backscattering Spectrometry (RBS) and micro-Particle Induced X-Ray Emission (uPIXE) was tested to evaluate both diffusion profiles and radionuclide spatial distribution of radionuclides (RN) onto cement-based materials. The methodology was tested on a Spanish reference backfill concrete, used as engineering barrier in low-level radioactive waste repositories, using two elements (Cs and I) with different sorption behaviour onto the cement. The applicability and limitations of the selected methodology is discussed for both elements.

Characterization of Natural and Synthesized FeTiO3 Crystals With RBS/PIXE/XRD

1997 ◽  
Vol 07 (03n04) ◽  
pp. 265-275
Author(s):  
R. Q. Zhang ◽  
S. Yamamoto ◽  
Z. N. Dai ◽  
K. Narumi ◽  
A. Miyashita ◽  
...  
Keyword(s):  
Single Crystals ◽  
Ion Beam ◽  
Pressure Control ◽  
Floating Zone ◽  
X Ray Diffraction ◽  
X Ray ◽  
Beam Analysis ◽  
Ppm Level

Natural FeTiO 3 (illuminate) and synthesized FeTiO 3, single crystals were characterized by Rutherford backscattering spectroscopy combined with channeling technique and particle-induced x-ray emission (RBS-C and PIXE). The results obtained by the ion beam analysis were supplemented by the x-ray diffraction analysis to identify the crystallographic phase. Oriented single crystals of synthesized FeTiO 3 were grown under the pressure control of CO 2 and H 2 mixture gas using a single-crystal floating zone technique. The crystal quality of synthesized FeTiO 3 single crystals could be improved by the thermal treatment but the exact pressure control is needed to avoid the precipitation of Fe 2 O 3 even during the annealing procedure. Natural FeTiO 3 contains several kinds of impurities such as Mn , Mg , Na and Si . The synthesized samples contain Al , Si and Na which are around 100 ppm level as impurities. The PBS-C results of the natural sample imply that Mn impurities occupy the Fe sublattice in FeTiO 3 or in mixed phase between ilmenite and hematite.

scholarly journals Characterization of Ti/SnO2 Interface by X-ray Photoelectron Spectroscopy

Nanomaterials ◽  
2022 ◽  
Vol 12 (2) ◽  
pp. 202
Author(s):  
Miranda Martinez ◽  
Anil R. Chourasia
Keyword(s):  
Photoelectron Spectroscopy ◽  
Room Temperature ◽  
Chemical Interaction ◽  
Photoelectron Spectra ◽  
X Ray ◽  
Increasing Trend ◽  
Substrate Temperatures ◽  
Beam Technique

The Ti/SnO2 interface has been investigated in situ via the technique of x-ray photoelectron spectroscopy. Thin films (in the range from 0.3 to 1.1 nm) of titanium were deposited on SnO2 substrates via the e-beam technique. The deposition was carried out at two different substrate temperatures, namely room temperature and 200 °C. The photoelectron spectra of tin and titanium in the samples were found to exhibit significant differences upon comparison with the corresponding elemental and the oxide spectra. These changes result from chemical interaction between SnO2 and the titanium overlayer at the interface. The SnO2 was observed to be reduced to elemental tin while the titanium overlayer was observed to become oxidized. Complete reduction of SnO2 to elemental tin did not occur even for the lowest thickness of the titanium overlayer. The interfaces in both the types of the samples were observed to consist of elemental Sn, SnO2, elemental titanium, TiO2, and Ti-suboxide. The relative percentages of the constituents at the interface have been estimated by curve fitting the spectral data with the corresponding elemental and the oxide spectra. In the 200 °C samples, thermal diffusion of the titanium overlayer was observed. This resulted in the complete oxidation of the titanium overlayer to TiO2 upto a thickness of 0.9 nm of the overlayer. Elemental titanium resulting from the unreacted overlayer was observed to be more in the room temperature samples. The room temperature samples showed variation around 20% for the Ti-suboxide while an increasing trend was observed in the 200 °C samples.

Structural Characterization of Ion Beam Enhanced Solid Phase Epitaxial Regrowth by Raman, RBS, and X-Ray Analysis

1988 ◽  
Vol 126 ◽  
Author(s):  
John F. Knudsen ◽  
R. C. Bowman ◽  
P. M. Adams ◽  
R. Newman ◽  
J. P. Hurrell ◽  
...  
Keyword(s):  
Solid Phase ◽  
Ion Beam ◽  
Beam Current ◽  
Crystalline Quality ◽  
X Ray Diffraction ◽  
X Ray ◽  
Epitaxial Regrowth ◽  
High Beam Current

ABSTRACTEpitaxial regrowth of deposited amorphous silicon has been previously described utilizing ion implantation amorphization, ion mixing and thermal anneal. This paper evaluates the effects of these process steps on crystalline quality utilizing Rutherford Backscattering (RBS), x-ray diffraction rocking curves and Raman scattering.In situ (during implantation) regrowth results in defective crystallinity. In contrast, when there is no in situ regrowth, the post anneal crystallinity is equivalent by RBS and x-ray evaluation to virgin single crystal wafers. In situ regrowth is most pronounced during the high beam current ion mixing type implants which produce wafer temperatures of about 250°C. The final crystalline quality which results from different sequences of amorphization and ion mixing implants, is strongly dependent upon the amount of in situ regrowth which has occurred. The greater the in situ regrowth the poorer the final crystalline quality.

Solid State Synthesis and Characterization of Spintronics Material Cd0.55 Hg0.45 Te

2010 ◽  
Vol 44-47 ◽  
pp. 2299-2306
Author(s):  
H.M.Noor Ul Huda Khan Asghar ◽  
M. Asghar ◽  
M.S. Awan
Keyword(s):  
Solid State ◽  
Synthesis And Characterization ◽  
Chemical Analyses ◽  
X Ray Diffraction ◽  
Conventional Solid State Reaction ◽  
Cubic Crystal ◽  
X Ray ◽  
Edx Analyses ◽  
Scanning Electron

Polycrystalline spintronic material (Cd0.55Hg0.45Te) was synthesized by conventional solid state reaction. The samples ( = 5 mm and T = 1.5 mm) were prepared by uni-axial pressing. Samples were melted at 800°C for 3-2 hours. For chemical analyses, surface morphology and structural analyses, scanning electron microscopy (SEM) equipped with EDX system and X-ray diffraction studies were performed. XRD confirmed the cubic crystal structure. The Lattice constant of (Cd0.55Hg0.45Te) as determined by XRD was 0.6464 nm. The Miller indices (hkl) have been found by using crystallography method. The observed planes were (200), (210) and (331). The EDX analyses showed the typically compositions: Te 24.8% Cd 14.8% Al 5% and O2 46.4 % & C 9% (3 hours treatment) and Te 28.1% Cd 16% Al 4.1% and O2 39.3 %, Si 0.360% & C 12.1% (2 hours treatment) however we could not find any representative peak for Hg in all of the EDX analyses.

scholarly journals Characterization of 4H Silicon Carbide Films Grown by Solvent-Laser Heated Floating Zone

2012 ◽  
Vol 1433 ◽  
Author(s):  
Andrew A. Woodworth ◽  
Ali Sayir ◽  
Philip G. Neudeck ◽  
Balaji Raghothamachar ◽  
Michael Dudley
Keyword(s):  
Silicon Carbide ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Growth Front ◽  
Electrical Performance ◽  
Floating Zone ◽  
X Ray ◽  
Growth Method ◽  
Laser Heated

ABSTRACTCommercially available bulk silicon carbide (SiC) has a high number (>2000/cm2) of screw dislocations (SD) that have been linked to degradation of high-field power device electrical performance properties. Researchers at the NASA Glenn Research Center have proposed a method to mass-produce significantly higher quality bulk SiC. In order for this bulk growth method to become reality, growth of long single crystal SiC fibers must first be achieved. Therefore, a new growth method, Solvent-Laser Heated Floating Zone (Solvent-LHFZ), has been implemented. While some of the initial Solvent-LHFZ results have recently been reported, this paper focuses on further characterization of grown crystals and their growth fronts. To this end, secondary ion mass spectroscopy (SIMS) depth profiles, cross section analysis by focused ion beam (FIB) milling and mechanical polishing, and orientation and structural characterization by X-ray transmission Laue diffraction patterns and X-ray topography were used. Results paint a picture of a chaotic growth front, with Fe incorporation dependant on C concentration.

scholarly journals SYNTHESIS AND CHARACTERIZATION OF CALCIUM SILICATE FROM RICE HUSK ASH AND SNAIL SHELL

2019 ◽  
Vol 11 (2) ◽  
pp. 45
Author(s):  
Sadang Husain ◽  
Ninis Hadi Haryanti ◽  
Suryajaya Suryajaya ◽  
Antung Permitaria
Keyword(s):  
Rice Husk ◽  
Calcium Silicate ◽  
Rice Husk Ash ◽  
Wave Number ◽  
X Ray Diffraction ◽  
Solid Reaction ◽  
Snail Shell ◽  
X Ray ◽  
Infra Red

<p class="abstrak">Calcium silicate ceramics have been made using natural ingredients such as rice husk and snail shell with solid reaction techniques. The aim of this study to determine the characteristics of calcium silicate that have been sintered at a temperature of 900 <sup>°</sup>C, 1000 <sup>°</sup>C, and 1100 <sup>°</sup>C. Samples were characterized by X-Ray Diffraction (XRD), optical microscopy, and Fourier Transform Infra-Red (FTIR). The results of XRD characterization showed that CaSiO<sub>3</sub> (calcium silicate) along with the increase in calcination temperature and quantity was increased due to the increase of temperature of calcination. FTIR analysis showed that the Ca-Si-O bond was formed at wave number ranging from 848 cm<sup>-1</sup> and 999 – 1001 cm<sup>-1</sup>.</p>

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