Combined Tem and X-Ray Topographic Characterization of InxGa1−xAs/GaAs Strained Layer Systems.

1990 ◽  
Vol 209 ◽  
Author(s):  
Michael Dudley ◽  
Gong-Da Yao ◽  
David Paine ◽  
David Howard ◽  
Robert N. Sacks
Keyword(s):  
Interfacial Dislocation ◽  
X Ray ◽  
Strained Layer ◽  
Dislocation Densities ◽  
Wide Range ◽  
Lift Off ◽  
Depth Sensitivity ◽  
Non Destructive ◽  
Defect Densities

ABSTRACTNovel application of a combination of TEM and non-destructive synchrotron X-ray topography in both Bragg and grazing Bragg-Laue geometries to the characterization of InxGa1−xAs/GaAs strained layer films is reported. Specialized epilayer lift-off procedures enabled TEM characterization of the defect distributions in macroscopic area films, effectively increasing the field of view of the technique by several orders of magnitude. These lateral distributions correlated well with those observed on both Bragg and grazing Bragg- Laue topographs. Grazing Bragg-Laue images also afforded depth sensitivity. Excellent correlations exist between results obtained with all these techniques for systems with a wide range of In concentrations, corresponding to a broad range of interfacial dislocation densities, although only results for x=;0.085 are presented. This work demonstrates that it is possible to bridge the gap that has traditionally existed between the areas of application of these two generic techniques, in terms of both tolerable defect densities and fields of view. This gap also spans the range of defect densities which is of interest in this and other systems.

scholarly journals X-Ray Fluorescence Analysis of a Gold Ibex and other Artifacts from Akrotiri

2019 ◽  
Vol 11 ◽  
Author(s):  
A. G. Karydas ◽  
T. Pantazis ◽  
C. Doumas ◽  
A. Vlachopoulos ◽  
P. Nomikos ◽  
...  
Keyword(s):  
Bulk Composition ◽  
Fluorescence Analysis ◽  
Wall Painting ◽  
Inorganic Elements ◽  
X Ray ◽  
Wide Range ◽  
Soldering Technology ◽  
Excavation Area

In-situ X-ray fluorescence analysis (XRF) of ancient artifacts from the excavation area was performed using a novel X-ray instrumentation, composed of a portable silicon PIN thermoelectrically cooled X-ray detector, a miniature X-ray source, and portable data acquisition devices. The main objective of the analyses in Akrotiri was to explore the potential of the technique to provide answers to a wide range of archaeometric questions regarding the bulk composition of metal alloys, especially of gold, the characterization of corrosion products in bronze artifacts, identification of inorganic elements which are fingerprints of the minerals used in wall-painting pigments, and of the painting materials and techniques used for the decoration of clay vase surfaces. Among the analysed artifacts are a unique gold ibex, a bronze dagger and blade, various pigments from the wall paintings of room 3 in Xeste 3, decoration pigments from rosettes of faience, a bichrome jug, and other clay vases. The results of the in-situ XRF survey, primarily those of the bulk composition and soldering technology of the gold ibex, are discussed and compared with literature.

scholarly journals Elements Identification in Golden Strawberries (Physalis Peruviana L.) using Wavelength Dispersive X-Ray Fluorescence

2019 ◽  
Vol 7 (6) ◽  
pp. 851
Author(s):  
Uğur Akbaba
Keyword(s):  
Weight Loss ◽  
Functional Food ◽  
Medical Field ◽  
X Ray ◽  
Physalis Peruviana ◽  
Food Properties ◽  
Wide Range ◽  
Important Health ◽  
Fluorescence Spectrometer ◽  
Non Destructive

Physalis peruviana (PP) is a popular exotic fruit due to its functional food properties. This product has a wide range of uses in the medical field, including treatments for cancer, malaria, hepatitis, dermatitis, rheumatism, weight loss, and diabetes. In this study, the PP element concentrations were investigated using a Wave Dispersive X-ray Fluorescence Spectrometer (WDXRF). Al, Ca, Fe, Mn, P, S, Zn, Cl, K, Mg, Na, F, Si, and B were detected, and the Ca, Fe, Zn, P, Na, Mg elements were found in significant amounts. Therefore, PP has some important health elements. For example, Mg and Mn may be associated with diabetes control. WDXRF is a cheap, quick, and non-destructive technique used in the elemental analysis of plant samples.

Single Crystal Wurtzitic Aluminum Nitride Growth on Silicon Using Supersonic Gas Jets

1995 ◽  
Vol 395 ◽  
Author(s):  
S. A. Ustin ◽  
L. Lauhon ◽  
K. A. Brown ◽  
D. Q. Hu ◽  
W. Ho
Keyword(s):  
Aluminum Nitride ◽  
Growth Rates ◽  
High Energy ◽  
X Ray Diffraction ◽  
Rutherford Back Scattering ◽  
X Ray ◽  
Supersonic Molecular Beam ◽  
Supersonic Beams ◽  
Wide Range

ABSTRACTHighly oriented aluminum nitride (0001) films have been grown on Si(001) and Si (111) substrates at temperatures between 550° C and 775° C with dual supersonic molecular beam sources. Triethylaluminum (TEA;[(C2H5)3Al]) and ammonia (NH3) were used as precursors. Hydrogen, helium, and nitrogen were used as seeding gases for the precursors, providing a wide range of possible kinetic energies for the supersonic beams due to the disparate masses of the seed gases. Growth rates of AIN were found to depend strongly on the substrate orientation and the kinetic energy of the incident precursor; a significant increase in growth rate is seen when seeding in hydrogen or helium as opposed to nitrogen. Growth rates were 2–3 times greater on Si(001) than on Si(111). Structural characterization of the films was done by reflection high energy electron diffraction (RHEED) and x-ray diffraction (XRD). X-ray rocking curve (XRC) full-width half-maxima (FWHM) were seen as small as 2.5°. Rutherford back scattering (RBS) was used to determine the thickness of the films and their chemical composition. Films were shown to be nitrogen rich, deviating from perfect stoichiometry by 10%–20%. Surface analysis was performed by Auger electron spectroscopy (AES).

Handheld Portable Energy-Dispersive X-Ray Fluorescence Spectrometry (pXRF)

2016 ◽  
pp. 362-381 ◽  
Author(s):  
Elisabeth Holmqvist
Keyword(s):  
Production Systems ◽  
Matrix Effects ◽  
Chemical Characterization ◽  
High Sensitivity ◽  
Limited Range ◽  
Energy Dispersive ◽  
Analytical Sensitivity ◽  
X Ray ◽  
Non Destructive

Handheld portable energy-dispersive X-ray fluorescence (pXRF) spectrometry is used for non-destructive chemical characterization of archaeological ceramics. Portable XRF can provide adequate analytical sensitivity to discriminate geochemically distinct ceramic pastes, and to identify compositional clusters that correlate with data patterns acquired by NAA or other high sensitivity techniques. However, successful non-destructive analysis of unprepared inhomogeneous ceramic samples requires matrix-defined scientific protocols to control matrix effects which reduce the sensitivity and precision of the instrumentation. Quantification of the measured fluorescence intensities into absolute concentration values and detection of light elements is encumbered by the lack of matrix matched calibration and proper vacuum facilities. Nevertheless, semi-quantitative values for a limited range of high Z elements can be generated. Unstandardized results are difficult to validate by others, and decreased analytical resolution of non-destructive surface analysis may disadvantage site-specific sourcing, jeopardize correct group assignments, and lead to under-interpretation of ceramic craft and production systems.

scholarly journals Synthesis and Crystallographic Characterization of X-Substituted 2,4-Dinitrophenyl-4′-phenylbenzenesulfonates

Chemistry ◽  
2020 ◽  
Vol 2 (2) ◽  
pp. 591-599
Author(s):  
Brock A. Stenfors ◽  
Richard J. Staples ◽  
Shannon M. Biros ◽  
Felix N. Ngassa
Keyword(s):  
Diffraction Data ◽  
Pyridinium Salt ◽  
Environmentally Benign ◽  
Pyridinium Salts ◽  
X Ray Diffraction ◽  
X Ray ◽  
Wide Range ◽  
Aqueous Environments ◽  
Aqueous Base

Treatment of 2,4-dinitrophenol with sulfonyl chlorides in the presence of pyridine results in the formation of undesired pyridinium salts. In non-aqueous environments, the formation of the insoluble pyridinium salt greatly affects the formation of the desired product. A facile method of producing the desired sulfonate involves the use of an aqueous base with a water-miscible solvent. Herein, we present the optimization of methods for the formation of sulfonates and its application in the production of desired x-substituted 2,4-dinitrophenyl-4′-phenylbenzenesulfonates. This strategy is environmentally benign and supports a wide range of starting materials. Additionally, the intermolecular interactions of these sulfonate compounds were investigated using single-crystal x-ray diffraction data.

scholarly journals Applications with a brighter X-ray source and new detectors from Agilent

2014 ◽  
Vol 70 (a1) ◽  
pp. C1734-C1734
Author(s):  
Zoltan Gal ◽  
Tadeusz Skarzynski ◽  
Fraser White ◽  
Oliver Presly ◽  
Adrian Jones ◽  
...  
Keyword(s):  
Data Quality ◽  
Single Crystal ◽  
Measurement System ◽  
Single Crystal Diffraction ◽  
X Ray ◽  
Vacuum Technology ◽  
Intelligent Measurement ◽  
Wide Range

Agilent Technologies develop and supply X-ray systems for single-crystal diffraction research, including the SuperNova; a compact, highly reliable and very low maintenance instrument providing X-ray data of the highest quality; and the PX Scanner for testing and characterization of protein crystals in their original crystallization drops (in-situ). The SuperNova and PX Scanner are constantly improving, with recent enhancements including a new range of detectors using an Intelligent Measurement System. The Eos S2, Atlas S2 and Titan S2 detector range employs a smart sensitivity control of the electronic gain and is capable of instantaneously switching its binning modes thus providing unprecedented flexibility in tuning every exposure to provide the highest data quality for a wide range of experiments. We have also developed a completely new micro-focus X-ray source based on Gradient Vacuum technology, with novel filament and target designs. This novel source is an integral part of the new Agilent GV1000 X-ray diffractometer, which has been designed for applications that require even higher brightness of the X-ray beam.

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