scholarly journals An X-ray Optical Method for the Determination of Diffusion Properties in Very Thin Bimetallic Films

1975 ◽  
Vol 30 (12) ◽  
pp. 1648-1654
Author(s):  
A. Wagendristel
Keyword(s):  
Alloy Formation ◽  
Experimental Check ◽  
X Ray ◽  
Enhanced Diffusion ◽  
Diffusion Parameters ◽  
Diffusion Rates ◽  
Bimetallic Films ◽  
Good Agreement ◽  
Diffusion Properties

Abstract The change of x-ray optical properties during diffusional alloy formation can be used for the evaluation of diffusion parameters in bimetallic thin film couples. The most pronounced phenomenon governed by these properties are the known Kiessig interferences which can be observed in the specular scattered x-ray beam at very small glancing angles. From these interference patterns diffusion data can be obtained by a comparison with calculated reflection curves based on a proper model for diffusion.The most useful thickness range for this method is below 1000 Å, where common x-ray techniques lose their applicability. Since the changes in the interference patterns are most significant in the early diffusion stages, this technique is most suitable for observing initial interdiffusion, which very often occurs with enhanced diffusion rates.The experimental check of the method is performed in the Au-Ag system. Bimetallic films of the pure components were annealed at temperatures between 200 and 300 °C. In this temperature range diffusion parameters from 10-16 to 10-14 cm2/s were found in good agreement with values obtained by other techniques.

The Study of the Interaction of the Components of Imitator-Glasses of Glassified Radioactive Wastes With Various Surrounding Rocks

1981 ◽  
Vol 6 ◽  
Author(s):  
V. I. Spitsyn ◽  
A. A. Minaev ◽  
L. I. Barsova ◽  
P. Ya. Glazunov ◽  
V. N. Vetchkanov
Keyword(s):  
Gamma Irradiation ◽  
High Temperatures ◽  
Phosphate Glass ◽  
Phosphate Glasses ◽  
Radioactive Wastes ◽  
X Ray ◽  
Enhanced Diffusion ◽  
Radiation Enhanced Diffusion

ABSTRACTThis work is one of the first attempts to work out a proper technique for the determination of the diffusion of the phosphate glass components into various rocks by using X-ray microanalysis. Under study was thermal and radiationenhanced diffusion of phosphorus, chromium from phosphate glasses into the samples of basalt, metagabbro, metadunite and quartz at high temperatures (to 600°) during gamma irradiation. Radiation enhanced diffusion of ions into rocks.

X-Ray Fluorescence Minor- and Trace-Element Analyses Silicate Rocks in the Presence of Large Interelement Effects

1977 ◽  
Vol 21 ◽  
pp. 75-88
Author(s):  
B. S. King ◽  
L. F. Espos ◽  
B. P. Fabbi
Keyword(s):  
Matrix Effects ◽  
Dilution Method ◽  
Regression Equations ◽  
X Ray ◽  
Geological Materials ◽  
Accuracy And Precision ◽  
Binder Ratio ◽  
Silicate Rocks ◽  
Good Agreement

An X-ray fluorescence (XRF) method has been devised for the rapid quantitative determination of 16 minor and trace elements in geological materials. This method, a modification of a direct dilution method (1, 2, 3), uses a sample-to-binder ratio of 85:15 for sample preparation. Pellets prepared by this method are durable and do not deteriorate rapidly when exposed to high X-ray irradiation. Interferences and matrix effects are successfully corrected in actual analyses by employment of multiple linear regression equations.Accuracy and precision have been improved over the method previously used in this laboratory. Detection limits have been lowered for Zn, Rb, Y and Zn approximately by the factor of 2. When interelement corrections are made, the XRF values are found to be in good agreement with the preferred chemical values for the 19 international silicate-rock standards.

Quantitative Determination of Carbon in Solid Hydrocarbons Using the Intensity Ratio of Incoherent to Coherent Scattering of X-Rays

1964 ◽  
Vol 18 (6) ◽  
pp. 171-174 ◽  
Author(s):  
C. J. Toussaint ◽  
G. Vos
Keyword(s):  
Intensity Ratio ◽  
Coherent Scattering ◽  
X Rays ◽  
Ray Method ◽  
Sample Weight ◽  
X Ray ◽  
Carbon Determination ◽  
Solid Hydrocarbons ◽  
Good Agreement

A method is presented for the determination of carbon in solid hydrocarbons using the intensity ratio of incoherent to coherent scattering of x-rays. The method is very rapid with precision at the 95% confidence level of about ±0.3%. The minimum sample weight necessary is 0 2 g. Analysis of samples by the x-ray method shows good agreement with values obtained by microcombustion. Finally a general comparison between different methods for carbon determination in solid hydrocarbons is discussed.

scholarly journals Divergent-beam X-ray photography of crystals

1947 ◽  
Vol 240 (817) ◽  
pp. 219-250 ◽  
Keyword(s):  
Wave Length ◽  
Impurity Content ◽  
Type I ◽  
X Rays ◽  
Divergent Beam ◽  
X Ray ◽  
Air Temperatures ◽  
High Degree ◽  
Good Agreement

Divergent-beam X-ray photography of single crystals by transmission can be used to study the ‘extinction’, that is, the diminution of the transmitted radiation that takes place at the Bragg reflexion angles. The intensity and geometry of the absorption lines observed give useful information about the texture of the crystal. Divergent beam photographs have shown that many crystals of organic compounds are unexpectedly perfect, and that sudden cooling to liquid-air temperatures will increase the mosaic character of their structure by an important factor and make them more suitable for structural analysis by the usual methods. Type I diamonds, and natural ice even near to its melting-point, are also found to possess a high degree of perfection, which cannot be removed by liquid-air treatment. The divergent beam method may be used for the determination of orientation, but it is important that the wave-length of X-rays employed should be correctly related to the size and nature of the crystal. In certain favourable cases it is possible to make precision measurements of lattice constant or of wave-length from divergent beam photographs, without the use of any kind of precision apparatus. By such means it has been shown that the C—C distance in individual diamonds varies from 1541.53(± 0-02) to 1541.27X, (1.54465-1-54440A), a difference presumably due to varying impurity content. Using diamond and a brass anticathode, the Zn Ka 1 wave-length, relative to Cu K Ka 1 as 1537.40X, is found to be 1432.21 ( ± 0-04) X. Temperature control would improve the accuracy of this measurement, which is, however, in good agreement with the latest value obtained by orthodox precision methods.

Determination of the Crystal Alignment of Pr-Fe-B Magnets Using the (105) X-Ray Pole Figure

2010 ◽  
Vol 660-661 ◽  
pp. 139-144 ◽  
Author(s):  
A.R.M. Castro ◽  
Hidetoshi Takiishi ◽  
Rubens Nunes de Faria Jr. ◽  
Nelson Batista de Lima
Keyword(s):  
Pole Figure ◽  
Permanent Magnets ◽  
X Ray ◽  
Sintered Magnets ◽  
Crystal Alignment ◽  
High Degree ◽  
Good Agreement

The crystallographic alignment of various permanent magnets has been investigated by X-ray pole figure analysis. Attempts have been made to measure the degree of alignment of these sintered magnets using the (105) reflection. It has been shown that the (105) pole figure can be used only to verify small differences in texture in magnets high degree of crystallographic alignment. A comparison between the measured and the calculated L105 index showed good agreement.

Phase analysis of sintered yttria–zirconia ceramics by x-ray diffraction

1986 ◽  
Vol 1 (2) ◽  
pp. 295-299 ◽  
Author(s):  
A. Paterson ◽  
R. Stevens
Keyword(s):  
Tetragonal Phase ◽  
Cubic Phase ◽  
X Ray Diffraction ◽  
Zirconia Ceramics ◽  
X Ray ◽  
Different Temperatures ◽  
Shear Transformation ◽  
Original Amount ◽  
Good Agreement

Determination of the amount of cubic and tetragonal phase in yttria–zirconia using high-angle XRD (x-ray diffraction) has been complicated by problems of resolution and interpretation. The evidence, from electron diffraction studies, for a c→t shear transformation also needs to be taken into account. Two compositions, a 3 and a 5.7 mol % Y2O3−ZrO2, were sintered and thermally treated at different temperatures between 1450°and 1700°C. X-ray diffraction traces revealed the anticipated tetragonal (400) and (004) reflections. The region of the diffraction pattern that was thought to arise from the cubic phase could be best interpreted as a second tetragonal phase t'. The original amount of cubic phase computed from the t' reflections showed good agreement with the phase diagram of Scott. The lattice parameters of the t' phase were determined, and the volume of the tetragonal (t') unit cell was calculated.

scholarly journals Real-time measurement system for determining metal concentrations in water-intensive processes

2020 ◽  
Vol 10 (1) ◽  
pp. 512-518
Author(s):  
Ekaterina Nikolskaya ◽  
Mika Liukkonen ◽  
Yrjö Hiltunen
Keyword(s):  
Metal Ions ◽  
Relaxation Rate ◽  
Metal Ion ◽  
Chemical Speciation ◽  
X Ray ◽  
Real Time Measurement ◽  
Paramagnetic Ions ◽  
Mining Water ◽  
Good Agreement

AbstractThe main purpose of this paper is to demonstrate the potential of time-domain nuclear magnetic resonance (TD-NMR) technology for monitoring the concentrations of metal ions in water-based solutions. The main focus of this work was paramagnetic ions, such as Mn2+, Cu2+, Fe3+, Fe2+, Zn2+ and Ni2+, which are often the principal metal components in mining waters. Laboratory samples of different concentrations of single metals and mixtures of them and samples of real mining water were used in the relaxation rate (R2) measurements. The measurements of single metal ions were used for the determination of the relaxivities of those ions. The concentrations of the ions in the mining water as a function of pH were also estimated by means of the X-ray fluorescence (XRF) method and ChemEQL software for calculating chemical speciation equilibria. Using these concentration values and the relaxivities of the metal ions, the total relaxation rate (R2) results were then calculated. Principally, the results of these three different determinations are in relatively good agreement. It can be concluded that TD-NMR has great potential for monitoring metal ion concentrations during water treatment.

scholarly journals Determination of Relativistic Intensity of X-Ray Diffracted from Aluminum Element.

2019 ◽  
Vol 24 (4) ◽  
pp. 74
Author(s):  
Muhsin Hasan Ali ◽  
Noor Mustafa Fadel
Keyword(s):  
Relative Intensity ◽  
The Other ◽  
X Ray ◽  
Other Hand ◽  
Good Agreement

In this paper, the relative intensity of X-ray diffracted from Aluminum (Al) was found, and taking into account the influences on the intensity of these rays. There was good agreement between the calculated and measured values, the simple differences between them can be attributed to the fact that all crystals in nature are real and not ideal crystals, on the other hand, the accuracy of atomic positions are must probably effected the calculated results   http://dx.doi.org/10.25130/tjps.24.2019.076

scholarly journals Assessment of geometrical and transport properties of a fibrous C/C composite preform as digitized by x-ray computerized microtomography: Part II. Heat and gas transport properties

2007 ◽  
Vol 22 (6) ◽  
pp. 1537-1550 ◽  
Author(s):  
Gerard L. Vignoles ◽  
Olivia Coindreau ◽  
Azita Ahmadi ◽  
Dominique Bernard
Keyword(s):  
Transport Properties ◽  
Pore Space ◽  
Three Dimensional ◽  
Carbon Composite ◽  
X Ray ◽  
Gas Transport Properties ◽  
Change Of Scale ◽  
Local Determination ◽  
Good Agreement

Raw and partially infiltrated carbon–carbon composite preforms have been scanned by high-resolution synchrotron radiation x-ray computerized microtomography. Three-dimensional high-quality images of the pore space have been produced at two distinct resolutions and have been used for the computation of transport properties: heat conductivity, binary gas diffusivities, Knudsen diffusivities, and viscous flow permeabilities. The computation procedures are based on a double change-of-scale strategy suited to the bimodal nature of pore space and on the local determination of transport anisotropy. Good agreement has been found between all calculated quantities and experimental data.

Bismuth on GaSb(110): Structural Determination of the 1×1 and 1×2 Phases by Surface X-Ray Diffraction

1998 ◽  
Vol 05 (05) ◽  
pp. 1043-1052 ◽  
Author(s):  
L. Lottermoser ◽  
T. Van Gemmeren ◽  
O. Bunk ◽  
R. L. Johnson ◽  
E. Landemark ◽  
...  
Keyword(s):  
Structural Model ◽  
Layer Structure ◽  
Zigzag Chain ◽  
X Ray Diffraction ◽  
Surface Geometry ◽  
X Ray ◽  
Reconstructed Surface ◽  
Thermal Stability Of ◽  
Good Agreement

The surface geometry of the 1×1 and 1×2 phases of bismuth on GaSb(110) has been determined using surface X-ray diffraction with synchrotron radiation. The bismuth atoms form zigzag chains along the [Formula: see text] direction of the substrate. For the 1×1 phase four different registries of the bismuth chains with respect to the GaSb(110) substrate are possible. It was found that only the epitaxial continued layer structure was in good agreement with the experimental data. In the 1×2 reconstruction every second zigzag chain in the uppermost substrate layer is missing. The reconstructed surface is terminated with a full monolayer of Bi atoms which also form zigzag chains. The Bi atoms in the chains bond alternately to the first and second layer substrate atoms and the Bi chains are inclined at 34° to the surface. This new structural model explains the higher thermal stability of the 1×2 phase compared to that of the 1×1 phase.

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