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Study of Extended X-Ray Absorption Fine Structure with the Use of Thick Targets

Published online by Cambridge University Press:  06 March 2019

J. T. Hach
Affiliation:
Materials Research Laboratory The Pennsylvania State University University Park, Pennsylvania
E. W. White
Affiliation:
Materials Research Laboratory The Pennsylvania State University University Park, Pennsylvania
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Abstract

A novel method has been investigated for the study of extended X-ray absorption-edge fine structures. The method takes advantage of the absorption of continuum X-rays that emerge at low takeoff angles from an electron-bombarded target. The extended fine structure is observed as undulations in the continuum X-ray intensity in the region of the self-absorption edge. Spectra from conventional X-ray diffraction tubes have been recorded for various values of kilovolts and takeoff angles. Spectra obtained by this method are compared with published data. Nearly all the features of the extended fine structures can be clearly resolved by this technique. In the case of iron ar.d copper targets, it is found, experimentally that the best contrast is obtained when using a 50-kV accelerating voltage. A takeoff angle of 3° yielded best results for copper, while an angle of 10° was best suited for iron. The Philibert absorption correction successfully used in electron microprobe analysis has been extended to account for the observed self-absorption effect where κΔλ = f(x)λ1/f(x)λ2. The primary advantage of the thick-target technique is in the ability to obtain absorption spectra without having to prepare thin films. The technique is essentially nondestructive in that the sample need not be pulverized or thinned.

Type
Research Article
Copyright
Copyright © International Centre for Diffraction Data 1967

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References

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