scholarly journals Soft X-Ray Absorption Spectra of Polyethyleneterephtalate (PET) Films ~ Mass Absorption Coefficient of Oxygen at the O K-Absorption Edge ~

2020 ◽  
Vol 63 (9) ◽  
pp. 470-475
Author(s):  
Yasuji MURAMATSU ◽  
Yuya MATSUMOTO ◽  
Eric M. GULLIKSON
Keyword(s):  
Absorption Coefficient ◽  
Absorption Spectra ◽  
Absorption Edge ◽  
Mass Absorption Coefficient ◽  
X Ray ◽  
Mass Absorption ◽  
X Ray Absorption ◽  
Pet Films

Measurement of Mass Absorption Coefficients Using Compton-Scattered Cu Radiation in X-ray Diffraction Analysis

1990 ◽  
Vol 34 ◽  
pp. 325-335 ◽  
Author(s):  
Steve J. Chipera ◽  
David L. Bish
Keyword(s):  
Chemical Composition ◽  
Solid State ◽  
Absorption Coefficient ◽  
Mass Absorption Coefficient ◽  
X Rays ◽  
X Ray Diffraction ◽  
Absorption Coefficients ◽  
Solid State Detector ◽  
X Ray ◽  
Mass Absorption

AbstractThe mass absorption coefficient is a useful parameter for quantitative characterization of materials. If the chemical composition of a sample is known, the mass absorption coefficient can be calculated directly. However, the mass absorption coefficient must be determined empirically if the chemical composition is unknown. Traditional methods for determining the mass absorption coefficient involve measuring the transmission of monochromatic X-rays through a sample of known thickness and density. Reynolds (1963,1967), however, proposed a method for determining the mass absorption coefficient by measuring the Compton or inelastic X-ray scattering from a sample using Mo radiation on an X-ray fluorescence spectrometer (XRF). With the recent advances in solid-state detectors/electronics for use with conventional powder diffractometers, it is now possible to readily determine mass absorption coefficients during routine X-ray diffraction (XRD) analyses.Using Cu Kα radiation and Reynolds’ method on a Siemens D-500 diffractometer fitted with a Kevex Si(Li) solid-state detector, we have measured the mass absorption coefficients of a suite of minerals and pure chemical compounds ranging in μ/ρ from graphite to Fe-metal (μ/ρ = 4.6-308 using Cu Kα radiation) to ±4.0% (lσ). The relationship between the known mass absorption coefficient and the inverse count rate is linear with a correlation coefficient of 0.997. Using mass absorption coefficients, phase abundances can be determined during quantitative XRD analysis without requiring the use of an internal standard, even when an amorphous component is present.

Mass Absorption Corrected X-Ray Powder Diffractograms. Part 1: Measuring Pyrite in Powdered Coals

1990 ◽  
Vol 5 (1) ◽  
pp. 44-47 ◽  
Author(s):  
David L. Wertz
Keyword(s):  
Absorption Coefficient ◽  
Limit Of Detection ◽  
Diffraction Peak ◽  
Mass Absorption Coefficient ◽  
Measured Intensity ◽  
X Ray ◽  
Mass Absorption ◽  
Powdered Coal ◽  
Analysis Protocol

AbstractAn X-ray analysis method has been developed for the quantitative analysis of pyrite (FeS2) in coals and lignites. Requiring neither the use of external or internal references, the method linearly relates diffraction peak area in the absorption corrected X-ray diffractogram obtained from the finely powdered coal to the pyrite abundance. The [311] diffraction peak of pyrite (FeS2) has been used to develop the analysis protocol. The Argonne premium coals have been used as the experimental subjects. The abundance of pyrite in each coal has been measured from the absorption corrected diffractograms, which has been constructed from the experimentally measured diffraction intensities and the mass absorption coefficient of each coal sample. The accuracy (accessed from the figure-of-merit and the net count uncertainty associated with the 1.63 Å pyrite peak) as well as the lower limit of detection for pyrite in these coals is presented. The role of the mass absorption coefficient in the conversion of the measured intensity to the absorption corrected intensity is discussed.

scholarly journals Finite lifetime broadening of calculated X-ray absorption spectra: possible artefacts close to the edge

2018 ◽  
Vol 25 (2) ◽  
pp. 523-528 ◽  
Author(s):  
Ondřej Šipr ◽  
Jiří Vackář ◽  
Ján Minár
Keyword(s):  
Absorption Spectra ◽  
Real Axis ◽  
Absorption Edge ◽  
Spectral Features ◽  
Core Hole ◽  
Energy Component ◽  
X Ray ◽  
The Core ◽  
X Ray Absorption ◽  
Small Imaginary Part

X-ray absorption spectra calculated within an effective one-electron approach have to be broadened to account for the finite lifetime of the core hole. For methods based on Green's function this can be achieved either by adding a small imaginary part to the energy or by convoluting the spectra on the real axis with a Lorentzian. By analyzing the FeK- andL2,3-edge spectra it is demonstrated that these procedures lead to identical results only for energies higher than a few core-level widths above the absorption edge. For energies close to the edge, spurious spectral features may appear if too much weight is put on broadeningviathe imaginary energy component. Special care should be taken for dichroic spectra at edges which comprise several exchange-split core levels, such as theL3-edge of 3dtransition metals.

VII.— An Investigation of the Absorption of Superposed X-radiations

1926 ◽  
Vol 45 (1) ◽  
pp. 48-58
Author(s):  
Wm. H. Watson
Keyword(s):  
Absorption Coefficient ◽  
Wave Length ◽  
Mass Absorption Coefficient ◽  
Critical Conditions ◽  
Characteristic Radiation ◽  
X Ray ◽  
Mass Absorption ◽  
Length Range

The first experiments on this subject were suggested by the absorption effects associated with the “J” phenomenon. In a comparison of the absorbability in aluminium and in copper of the radiation emitted in one direction from an X-ray tube, it is found that in many cases, as the tube is hardened and a certain value of the mass-absorption coefficient reached, there is a sudden increase in the absorption by aluminium. Since the radiation is not strictly homogeneous, and since the above effect does not invariably take place, it is evident that the phenomenon is not to be explained simply in terms of a “J” series characteristic radiation similar to K and L characteristic radiations as regards the manner of its excitation. It is evident that certain critical conditions must obtain before the phenomenon occurs, and on account of the abruptness of the change it appears as though the whole wave-length range of the radiation were affected in respect of absorption by aluminium. This seems to be further substantiated by the fact that the discontinuous character of the change in absorption is preserved with a beam which is much more heterogeneous.

Determination of mass absorption coefficient in two-layer thin-film Cr/V and V/Cr systems by X-ray fluorescence spectrometry

2017 ◽  
Vol 72 (11) ◽  
pp. 1167-1171 ◽  
Author(s):  
N. I. Mashin ◽  
E. A. Krylov ◽  
E. A. Chernyaeva ◽  
A. V. Ershov ◽  
E. O. Zimina
Keyword(s):  
Thin Film ◽  
Absorption Coefficient ◽  
Mass Absorption Coefficient ◽  
Fluorescence Spectrometry ◽  
X Ray ◽  
Mass Absorption ◽  
Layer Thin Film
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