Quantitative technique for the determination of the number of unoccupied d-electron states in a platinum catalyst using the L2,3 x-ray absorption edge spectra

1984 ◽  
Vol 88 (11) ◽  
pp. 2330-2334 ◽  
Author(s):  
A. N. Mansour ◽  
J. W. Cook ◽  
D. E. Sayers
Keyword(s):  
Absorption Edge ◽  
Platinum Catalyst ◽  
Electron States ◽  
X Ray ◽  
Quantitative Technique ◽  
X Ray Absorption

X-Ray Absorption-Edge Determination of Cobalt in Complex Mixtures*

1961 ◽  
Vol 5 ◽  
pp. 379-388
Author(s):  
E.A. Hakkila ◽  
G.R. Waterbury
Keyword(s):  
Nitric Acid ◽  
Absorption Edge ◽  
Path Length ◽  
Construction Materials ◽  
X Ray ◽  
Relative Standard ◽  
Standard Deviations ◽  
Low X ◽  
X Ray Absorption

AbstractThe application of the X-ray absorption-edge technique was extended to the determination of cobalt in aqueous and alcoholic solutions containing a wide variety of impurity elements. In the procedure developed, secondary radiation from a 50% copper-nickel alloy is passed through an absorption cell filled alternately with the solvent and the sample solution. The transmitted Intensities of the Kα lines for copper and nickel are measured, and the concentration of cobalt is determined using accepted absorption principles. The K absorption edge for cobalt occurs at 1.604 A, restricting cell construction materials and solvents to those containing light elements with low X-ray absorption characteristics and also limiting the path length of the cell.Cells of 0.16- and 0.34-cm path length were used in the analysis of aqueous and alcoholic solutions, respectively. With the 0.16-cm path-length cell, relative standard deviations of 4.6 to 0.5% were obtained for cobalt concentrations ranging from 1.00 to 10.00 mg/ml for known aqueous solutions that contain various known concentrations of nitric acid. With the longer path-length cell, relative standard deviations from 1.8 to 0.46% were obtained for cobalt concentrations in the same range in known alcoholic solutions containing various known concentrations of nitric acid. The standard deviation of determining the blank is 0.043 mg of cobalt per milliliter for the 0.16-cm cell and 0.016 mg of cobalt per milliliter for the longer cell.A Norelco X-ray spectrograph with a three-position head was used in these analyses. Less than 5 min is required to convert this instrument from normal fluorescence operation to absorption-edge analysis. Approximately 15 to 20 analyses can be performed daily.

A Versatile Vacuum Scahhihg Double Crystal Spectrometer for Soft X-Ray Absorption Edge Studies

1969 ◽  
Vol 13 ◽  
pp. 272-288
Author(s):  
A.S. Bhalla ◽  
E.W. White
Keyword(s):  
Absorption Edge ◽  
Vacuum Chamber ◽  
Wavelength Region ◽  
Materials Characterization ◽  
Resolving Power ◽  
Crystal Spectrometer ◽  
Double Crystal ◽  
X Ray ◽  
X Ray Absorption

Studies of the fine structure of absorption edges in the soft x-ray region are becoming increasingly important as a tool for materials characterization. Examples of application includes determination of chemical state of elements, bonding and band structure studies. Intensity and resolving power of the x-ray spectrometer are important experimental considerations. As a rule adjustment of instrumental parameters, such as collimation, to give increased intensity adversely affect resolving power. Optimization of intensity and resolving power must therefore he achieved.A newly designed double crystal spectrometer has been constructed for high-resolution absorption edge studies in the wavelength region of 5Ǻ to 70Ǻ.The entire system is enclosed in a vacuum chamber ion pumped to the 10-7 torr range. The second crystal motion is obtained by means of an ULTRADEX 360-sided polygon and sine arm that is automatically step-scanned. The spectrometer functions equally well in the (l, + l) and (l, - l) orientation and as a precise single crystal spectrometer.

Three-Wavelength X-Ray Absorption Edge Method for Determination of Plutonium in Nitrate Media.

1966 ◽  
Vol 38 (3) ◽  
pp. 425-427 ◽  
Author(s):  
E. A. Hakkila ◽  
R. G. Hurley ◽  
G. R. Waterbury
Keyword(s):  
Absorption Edge ◽  
X Ray ◽  
Edge Method ◽  
X Ray Absorption
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