Simultaneous Determination of Layer Thickness, Composition, and Mass Absorption by X-Ray Diffraction

1992 ◽  
Vol 7 (4) ◽  
pp. 194-196 ◽  
Author(s):  
Stefano Battaglia ◽  
Marco Franzini ◽  
Leonardo Leoni
Keyword(s):  
Absorption Coefficient ◽  
Simultaneous Determination ◽  
Mass Absorption Coefficient ◽  
Crystalline Substance ◽  
X Ray Diffraction ◽  
Mass Thickness ◽  
Mass Absorption ◽  
Crystalline Substrate ◽  
Quantitative Results

AbstractThis paper describes a new method for the simultaneous determination of mineral composition, mass thickness and mass absorption coefficient of a thin layer of a crystalline substance deposited on a crystalline substrate.The samples were deposited on membrane disc filters, consisting of mixtures of cellulose acetate and cellulose nitrate. Quantitative results are achieved by measuring the diffraction intensity of the analyte and the attenuation of a reflection of the crystalline material supporting the deposited sample. The mean accuracy of the analysis was found to be: ≈ 3% for mass thickness, ≈ 1% for mass absorption coefficient and ≈ 4% for quantitative mineralogical determination.

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.

Determination of the Mass Absorption Coefficient in Two-Layer Cr/Co Thin Film Systems by the X-Ray Fluorescence Method

2020 ◽  
Vol 86 (6) ◽  
pp. 1048-1052
Author(s):  
E. A. Cherniaeva ◽  
A. A. Knyazeva ◽  
E. O. Zimina ◽  
I. S. Belyakova ◽  
N. I. Mashin
Keyword(s):  
Thin Film ◽  
Absorption Coefficient ◽  
Fluorescence Method ◽  
Mass Absorption Coefficient ◽  
X Ray ◽  
Mass Absorption

The Use of Mass Absorption in Quantitative X-Ray Diffraction Analysis

1986 ◽  
Vol 30 ◽  
pp. 333-342 ◽  
Author(s):  
Briant L. Davis ◽  
L. Ronald Johnson
Keyword(s):  
Absorption Coefficient ◽  
Diffraction Analysis ◽  
Mass Absorption Coefficient ◽  
X Ray Diffraction ◽  
Internal Standards ◽  
Multicomponent Analysis ◽  
X Ray ◽  
Mass Absorption ◽  
External Standard ◽  
Absorption Measurements

The mass absorption coefficient is perhaps the most under-utilized parameter in x-ray diffraction analysis. Mass absorption measurements are often avoided in quantitative analysis by resorting to calibration curves of internal standards (e.g., Kung and Alexander, 1974, Sec. 7-2.1). However, Leroux et al. (1953) and Frevel and Roth (1982) directly utilized the mass absorption coefficient in multicomponent analysis, and suggested a "substrate diffraction" procedure for directly measuring the sample mass absorption coefficient. The reference intensity procedure of quantitative multicomponent analysis originally formulated by Frank Chung (1974) requires no explicit use of the mass absorption coefficient because all reference intensity ratios are determined relative to an "external" standard, generally corundum (Al2O3).

scholarly journals Spectral reflectance of solar light from dirty snow: a simple theoretical model and its validation

2013 ◽  
Vol 7 (4) ◽  
pp. 1325-1331 ◽  
Author(s):  
A. Kokhanovsky
Keyword(s):  
Absorption Coefficient ◽  
Climate Models ◽  
Mass Absorption Coefficient ◽  
Soot Concentration ◽  
Snow Layer ◽  
Snow Albedo ◽  
Mass Absorption ◽  
Simple Theoretical Model ◽  
Soot Mass

Abstract. A simple analytical equation for the snow albedo as the function of snow grain size, soot concentration, and soot mass absorption coefficient is presented. This simple equation can be used in climate models to assess the influence of snow pollution on snow albedo. It is shown that the squared logarithm of the albedo (in the visible) is directly proportional to the soot concentration. A new method of the determination of the soot mass absorption coefficient in snow is proposed. The equations derived are applied to a dusty snow layer as well.

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