A study of the influence of chemical environment on the L i ( i  = 1–3) subshell X ‐ray intensity ratios and the L 3 absorption‐edge energy for some compounds of 66 Dy using synchrotron radiation

2019 ◽  
Vol 48 (2) ◽  
pp. 126-137 ◽  
Author(s):  
Rajnish Kaur ◽  
Anil Kumar ◽  
Mateusz Czyzycki ◽  
Alessandro Migliori ◽  
Andreas G. Karydas ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Absorption Edge ◽  
Chemical Environment ◽  
X Ray ◽  
Absorption Edge Energy ◽  
Intensity Ratios

Escape Peaks in X-Ray Diffractometry*

1964 ◽  
Vol 8 ◽  
pp. 118-133 ◽  
Author(s):  
William Parrish
Keyword(s):  
Absorption Edge ◽  
Pulse Height ◽  
Pulse Amplitude ◽  
Silicon Powder ◽  
X Rays ◽  
Pulse Height Analyzer ◽  
Escape Peak ◽  
X Ray ◽  
Absorption Edge Energy ◽  
Detector Element

AbstractEscape peaks occur when the incident X-ray quantum, energy exceeds the absorption edge energy of the detector element and the resulting X-ray fluorescence is lost from the detector. The most common escape peaks result from 1 K-fluorescence in NaI-scintillation counters and Xe K-, Xe L-, and Kr K-fluorescence in proportional counters. The average pulse amplitude of the escape peak is proportional to the difference of the Energies of the incident and fluorescent X-rays. If the intensity of the escape peak is high as in the case of Mo Kα and a kryptoopreportional counter, and the lower level of the pulse height analyzer is raised to reject the escape peak, the quantum counting efficiency may be reduced by a factor of two. When the pulse height analyzer is set for characteristic incident radiation, escape peaks appear in powder patterns at small diffraction angles. These broad low-intensity peaks are often mistakenly identified as resulting from misalignment, scattering, etc. Each powder reflection can produce its own escape peak which occurs at an angle slightly smaller than the absorption edge of the detector element. In a silicon powder pattern the three strongest reflections produce three resolved escape peaks whose peak intensities are about 4% of their corresponding Cu Kα peaks when the X-ray tube is operated at 50 kV. The escape peak intensities decrease with decreasing X-ray tube voltage and disappear when the voltage is lower than the absorption edge energy of the detector element. Absorption edge peaks observed without the upper level of the pulse height analyzer are similar in appearance, intensity, and diffraction angle to the escape peaks. In complex powder patterns the escape peak pattern is unresolved and may produce a number of very broad peaks.

A method to stabilize the incident X-ray energy for anomalous diffraction measurements

2017 ◽  
Vol 24 (4) ◽  
pp. 781-786
Author(s):  
Wenjia Wang ◽  
Xiaoyun Yang ◽  
Guangcai Chang ◽  
Pengfei An ◽  
Kewen Cha ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Data Collection ◽  
Absorption Edge ◽  
Feedback Loop ◽  
Inflection Point ◽  
Single Crystal Diffraction ◽  
Double Crystal ◽  
Anomalous Diffraction ◽  
X Ray ◽  
Double Crystal Monochromator

A method to calibrate and stabilize the incident X-ray energy for anomalous diffraction data collection is provided and has been successfully used at the single-crystal diffraction beamline 1W2B at the Beijing Synchrotron Radiation Facilities. Employing a feedback loop to control the movement of the double-crystal monochromator, this new method enables the incident X-ray energy to be kept within a 0.2 eV range at the inflection point of the absorption edge.

Chemical microanalysis by x‐ray microscopy near absorption edge with synchrotron radiation

1977 ◽  
Vol 31 (11) ◽  
pp. 785-787 ◽  
Author(s):  
F. Polack ◽  
S. Lowenthal ◽  
Y. Petroff ◽  
Y. Farge
Keyword(s):  
Synchrotron Radiation ◽  
Absorption Edge ◽  
X Ray

scholarly journals X-Ray Microscopy Using Collimated and Focussed Synchrotron Radiation*

1987 ◽  
Vol 31 ◽  
pp. 59-68 ◽  
Author(s):  
K. W. Jones ◽  
W. M. Kwiatek ◽  
B. M. Gordon ◽  
A. L. Hanson ◽  
J. G. Pounds ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Absorption Edge ◽  
Periodic Table ◽  
Small Diameter ◽  
Biological Materials ◽  
X Rays ◽  
X Ray ◽  
Zone Plates ◽  
Elemental Maps

X-ray microscopy is a field that has developed rapidly in recent years. Two different approaches have been used. Zone plates have been employed to produce focussed beams with sizes as low as 0.07 pm for x-ray energies below 1 keV. Images of biological materials and elemental maps for major and minor low Z have been produced using above and below absorption edge differences. At higher energies collimators and focussing mirrors have been used to make small diameter beams for excitation of characteristic K— or L-x rays of all elements in the periodic table.

Development of X-ray photoemission electron microscopy (X-PEEM) at the SRS

1998 ◽  
Vol 5 (3) ◽  
pp. 1108-1110 ◽  
Author(s):  
A. D. Smith ◽  
G. Cressey ◽  
P. F. Schofield ◽  
B. A. Cressey
Keyword(s):  
Electron Microscopy ◽  
Iron Oxide ◽  
Synchrotron Radiation ◽  
Absorption Edge ◽  
Single Phase ◽  
Photoemission Electron Microscopy ◽  
X Ray ◽  
Limited Availability ◽  
Radiation Sources ◽  
Photoemission Electron

The use of synchrotron radiation sources for X-ray spectroscopy is a well known and developed field. The majority of applications, however, have been limited to studies of materials containing only a single phase of the element of interest. Owing to limited availability of suitable instrumentation, the study of materials comprising intergrowths of different phases has presented difficulties in analysis. The majority of natural materials, including mineralogical samples, fall into this category. However, by applying the technique of photoemission electron microscopy (PEEM) to view the X-ray stimulated photoemission generated at an absorption edge, micro-area-selectable spectroscopy becomes possible. An instrument for X-ray PEEM (X-PEEM) is being developed at the Daresbury SRS and this paper shows how it can be used to obtain characteristic L-edge XANES spectra from finely intergrown iron oxide minerals.

Measurements of X-Ray Anomalous Scattering Factors near the Cu K Absorption Edge by the Use of Synchrotron Radiation

1978 ◽  
Vol 17 (S2) ◽  
pp. 326 ◽  
Author(s):  
Tomoe Fukamachi ◽  
Sukeaki Hosoya ◽  
Takaaki Kawamura ◽  
Sally Hunter ◽  
Yuji Nakano
Keyword(s):  
Synchrotron Radiation ◽  
Absorption Edge ◽  
Anomalous Scattering ◽  
X Ray

Experimental evidence for onset of L1–L3M5 transition at Z = 75 through measurements of fluorescence and Coster–Kronig yields for W and Re

2021 ◽  
Author(s):  
Vibha Ayri ◽  
Sandeep Kaur ◽  
Anil Kumar ◽  
M. Czyzycki ◽  
A. G. Karydas ◽  
...  
Keyword(s):  
Synchrotron Radiation ◽  
Experimental Evidence ◽  
Absorption Edge ◽  
X Ray ◽  
Line Intensities ◽  
Radiation Induced

L shell fluorescence and Coster–Kronig yields for W and Re were deduced from synchrotron radiation induced X-ray line intensities measured at different incident energies across the Li absorption edge energies of both elements based on HFS and DHF models.

X-ray absorption near-edge structure anomalous behaviour in structures with buried layers containing silicon nanocrystals

2013 ◽  
Vol 21 (1) ◽  
pp. 209-214 ◽  
Author(s):  
V. A. Terekhov ◽  
D. I. Tetelbaum ◽  
D. E. Spirin ◽  
K. N. Pankov ◽  
A. N. Mikhailov ◽  
...  
Keyword(s):  
Silicon Carbide ◽  
Absorption Edge ◽  
Energy Region ◽  
Silicon Nanocrystals ◽  
Silicon Oxide ◽  
Abnormal Behaviour ◽  
Edge Structure ◽  
X Ray ◽  
Absorption Edge Energy ◽  
X Ray Absorption

Substructure and phase composition of silicon suboxide films containing silicon nanocrystals and implanted with carbon have been investigated by means of the X-ray absorption near-edge structure technique with the use of synchrotron radiation. It is shown that formation of silicon nanocrystals in the films' depth (more than 60 nm) and their following transformation into silicon carbide nanocrystals leads to abnormal behaviour of the X-ray absorption spectra in the elementary silicon absorption-edge energy region (100–104 eV) or in the silicon oxide absorption-edge energy region (104–110 eV). This abnormal behaviour is connected to X-ray elastic backscattering on silicon or silicon carbide nanocrystals located in the silicon oxide films depth.

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