Determination of Diffusion Coefficients with Quantitative X-Ray Microanalysis at High - Spatial Resolution

2012 ◽  
Vol 323-325 ◽  
pp. 61-67 ◽  
Author(s):  
Raynald Gauvin ◽  
Nicolas Brodusch ◽  
Pierre Michaud
Keyword(s):  
Diffusion Coefficient ◽  
Diffusion Coefficients ◽  
Beam Energy ◽  
High Spatial Resolution ◽  
Ratio Method ◽  
Concentration Profiles ◽  
X Ray ◽  
Advantages And Disadvantages ◽  
Scanning Electron

This paper present the determination of concentration profiles of an Mg Al diffusion couple that was obtained with a high resolution field emission scanning electron microscope, the Hitachi SU-8000 equipped with a SDD EDS detector. From these concentration profiles, the inter-diffusion coefficient is determined with the Boltzmann-Matano technique. The advantages and disadvantages of working at high and low beam energy for quantitative x-ray microanalysis are highlighted. The f ratio method is used in this work to convert the x-ray intensities into composition.

scholarly journals Determination of Diffusion Coefficients Using Thermogravimetric Measurements during High Temperature Oxidation

2012 ◽  
Vol 323-325 ◽  
pp. 289-294
Author(s):  
Patrice Berthod ◽  
Lionel Aranda
Keyword(s):  
Diffusion Coefficient ◽  
High Temperature ◽  
Diffusion Coefficients ◽  
High Temperature Oxidation ◽  
Concentration Profiles ◽  
Metallic Elements ◽  
Chromium Diffusion ◽  
Temperature Oxidation ◽  
Iron Based

Thermogravimetry measurements associated to concentration profiles allow determining a diffusion coefficient at high temperature of the most oxidable one among the metallic elements belonging to the chemical composition of an alloy. In this work the employed method is described and applied to chromia-forming alloys essentially based on nickel but also to selected cobalt-based and iron-based alloys. More precisely DCrvalues were estimated for chromium diffusing through the carbide-free zones developed during high temperature oxidation. The effects of the base element, of the chromium carbides density and of the dendritic orientations on the chromium diffusion were evidenced.

Sem and X-Ray Analysis of Renal and Biliary Calculi

1976 ◽  
Vol 34 ◽  
pp. 306-307
Author(s):  
R. J. Narconis ◽  
G. L. Johnson
Keyword(s):  
Chemical Constituents ◽  
Natural State ◽  
X Ray Diffraction ◽  
Chemical Methods ◽  
X Ray ◽  
Additional Dimension ◽  
Biliary Calculi ◽  
Calculus Formation ◽  
Scanning Electron

Analysis of the constituents of renal and biliary calculi may be of help in the management of patients with calculous disease. Several methods of analysis are available for identifying these constituents. Most common are chemical methods, optical crystallography, x-ray diffraction, and infrared spectroscopy. The application of a SEM with x-ray analysis capabilities should be considered as an additional alternative.A scanning electron microscope equipped with an x-ray “mapping” attachment offers an additional dimension in its ability to locate elemental constituents geographically, and thus, provide a clue in determination of possible metabolic etiology in calculus formation. The ability of this method to give an undisturbed view of adjacent layers of elements in their natural state is of advantage in determining the sequence of formation of subsequent layers of chemical constituents.

scholarly journals Migration of mineral oil in elastomers

2021 ◽  
Author(s):  
Tobias Förster ◽  
Artur Blivernitz
Keyword(s):  
Diffusion Coefficients ◽  
Mineral Oil ◽  
Activation Energies ◽  
Concentration Profiles ◽  
Small Reservoir ◽  
Experimental Procedure ◽  
Mineral Oils ◽  
The Absolute ◽  
Suitable Measure

AbstractThis work describes a newly introduced experimental procedure to quantify the diffusion progress of mineral oils locally resolved in NBR. Diffusion of reference oils IRM 901, IRM 902 and IRM 903 in NBR with various acrylonitrile contents was investigated. Classical sorption experiments were performed as a basic characterization and compared to the newly introduced method. Here, elastomer specimens are only being dipped with the bottom in a relatively small reservoir of mineral oil. This provides a determination of locally resolved concentration profiles of mineral oils, and the calculation of diffusion coefficients. These diffusion coefficients follow the same trends like those determined via sorption experiments. Despite differences in the absolute numbers, activation energies of diffusion can be applied as a suitable measure for the compatibility of elastomers and fluids.

scholarly journals Low Voltage Scanning Electron Microscopy

2002 ◽  
Vol 10 (2) ◽  
pp. 22-23 ◽  
Author(s):  
David C Joy ◽  
Dale E Newbury
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
High Spatial Resolution ◽  
Low Voltage ◽  
Incident Beam ◽  
Operational Mode ◽  
X Ray ◽  
Rapid Fall ◽  
Voltage Scanning ◽  
Scanning Electron

Low Voltage Scanning Electron Microscopy (LVSEM), defined as operation in the energy range below 5 keV, has become perhaps the most important single operational mode of the SEM. This is because the LVSEM offers advantages in the imaging of surfaces, in the observation of poorly conducting and insulating materials, and for high spatial resolution X-ray microanalysis. These benefits all occur because a reduction in the energy Eo of the incident beam leads to a rapid fall in the range R of the electrons since R ∼k.E01.66. The reduction in the penetration of the beam has important consequences.

Evaluation of computer-controlled SEM in the study of metal-contaminated soils

2003 ◽  
Vol 67 (2) ◽  
pp. 219-231 ◽  
Author(s):  
H. W. Langmi ◽  
J. Watt
Keyword(s):  
Electron Microscopy ◽  
Heavy Metals ◽  
Contaminated Soils ◽  
X Ray ◽  
Computer Controlled ◽  
Weathering Crusts ◽  
Individual Particles ◽  
Element Mapping ◽  
Scanning Electron

Computer-controlled scanning electron microscopy (CCSEM) has been assessed for the determination of form and size distribution of heavy metals in urban contaminated soils. Metal distributions within individual particles were determined using X-ray element mapping. The sites selected for study were (1) around a landfill site, previously a colliery in Wolverhampton, UK and (2) a private garden adjacent to a railway in Nottingham, UK. Backscattered thresholding techniques were used to isolate the Pb-containing categories. The classification results for both Wolverhampton and Nottingham soils were generally similar but more Pb-containing classes were observed for the Nottingham samples when a comparison was made between results of the same size fractions. However, difficulties with the technique arose when particles showing chemically similar weathering crusts were assigned to the same class, despite having different internal compositions. The CCSEM data therefore need to be interpreted with caution and their application limited to situations in which particle internal complexity is not an issue.

Lattice-constant and stress measurement in single crystals: a new method

2005 ◽  
Vol 38 (4) ◽  
pp. 678-684 ◽  
Author(s):  
Balder Ortner
Keyword(s):  
Single Crystal ◽  
Single Crystals ◽  
Lattice Constant ◽  
Stress Measurement ◽  
New Method ◽  
Lattice Plane ◽  
X Ray ◽  
Advantages And Disadvantages

A method for the X-ray determination of lattice-plane distances is given. Similar to Bond's method, it is based on the measurement of rocking curves, with some advantages and disadvantages compared with the former method. The new method is especially designed for single-crystal stress measurement. Its usefulness is demonstrated in two examples of lattice-constant and stress measurement.

scholarly journals The use of scanning electron microscopy to the study of the painting from the Church in Radcze

2013 ◽  
Vol 12 (4) ◽  
pp. 095-105
Author(s):  
Beata Klimek
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Electron Microscope ◽  
Historic Buildings ◽  
X Ray ◽  
Composition And Structure ◽  
The Church ◽  
Diagnosis Technique ◽  
Scanning Electron

One of the main tasks in the study of historic buildings is the need to identify the original materials and extensions, which often have historic character. The next task concerns the determination of the composition and structure of the historical, diagnosis technique to develop original paint. The article presents the preliminary results of paintings. Methods were used with the scanning electron microscope was equipped with an energy dispersive X-ray spectrometer (SEM-EDS).

X-Ray Diffraction and Reflectometry Investigation of Interdiffusion In Sputtered Niobium-Tungsten Bilayers

1999 ◽  
Vol 562 ◽  
Author(s):  
U. Welzel ◽  
P. Lamparter ◽  
E. J. Mittemeijer
Keyword(s):  
Diffusion Coefficients ◽  
Low Temperatures ◽  
Qualitative Evaluation ◽  
Diffraction Line ◽  
Published Data ◽  
Concentration Profiles ◽  
Line Broadening ◽  
X Ray Diffraction ◽  
Bulk Materials ◽  
X Ray

ABSTRACTInterdiffusion in sputtered niobium(45nm)-tungsten(45nm) bilayers upon annealing at low temperatures (T<1000K) has been investigated using X-ray reflectometry and diffraction. The accompanying changes in macrostress and microstructure have been characterized by applying the X-ray diffraction sin2ψ T method and by qualitative evaluation of the diffraction line broadening, respectively. Annealing causes, besides interdiffusion, changes of macrostress and decrease of microstructural imperfection. Concentration profiles corresponding to diffusion lengths of only a few nanometers were determined by simulation of the measured reflectivity patterns. The values obtained for the diffusion coefficients are compared with corresponding values obtained by extrapolation from published data for bulk materials at much higher temperatures.

Study of an Energetic-oxidant Co-crystal: Preparation, Characterisation, and Crystallisation Mechanism

2017 ◽  
Vol 67 (5) ◽  
pp. 510 ◽  
Author(s):  
Han Gao ◽  
Wei Jiang ◽  
Jie Liu ◽  
Gazi Hao ◽  
Lei Xiao ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Differential Scanning Calorimetry ◽  
Diffraction Spectrum ◽  
Solvent Evaporation Method ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Scanning Electron

<p>An energetic co-crystal consisting of the most promising military explosive 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane (CL-20) and the most well-known oxidant applied in propellants ammonium perchlorate has been prepared with a simple solvent evaporation method. Scanning electron microscopy revealed that the morphology of co-crystal differs greatly from each component. The X-ray diffraction spectrum, FTIR, Raman spectra, and differential scanning calorimetry characterisation further prove the formation of the co-crystal. The result of determination of hygroscopic rate indicated the hygroscopicity was effectively reduced. At last, the crystallisation mechanism has been discussed.</p>

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