X-ray fluorescence yield

In addition to qualitative identification of the elements present, XRF can be used to determine quantitative elemental compositions and layer thicknesses of thin films. In quantitative analysis the observed intensities must be corrected for various factors, including the spectral intensity distribution of the incident X rays, fluorescent yields, matrix enhancements and absorptions, etc. Two general methods used for making these corrections are the empirical parameters method and the fimdamen-tal parameters methods. 

E. Hartmann, X-ray fluorescence yields for light emitter atoms Carbon, J. Phys. B 21 (1988) 1173. 

The XSW field established inside the crystal and above the crystal surface induces photoelectron emission from atoms within the field. The excited atoms (ions), in turn, emit characteristic fluorescence X-rays and Auger electrons. In the dipole approximation, the photoelectric effect cross section is proportional to the E-field intensity at the center of the atom. (It is necessary to consider higher-order multi-pole terms in the photoelectric cross-section under special conditions, as discussed by Fischer et al. (1998) and Schreiber et al. (2001). For this review, we will assume the dipole approximation.) Therefore, with the XSW intensity from Equation (6), the normalized X-ray fluorescence yield is defined as... 

Baker DR (2002) The Hard X-ray Microprobe. In Synchrotron Radiation Earth, Environmental, and Material Sciences Applications. Short Course Series Vol. 30. Henderson GS and Baker DR (eds) Mineralogical Society of Canada, Ottawa, Canada, p 99-130 Bambynek W, Crasemann B, Fink RW, Freund HU, Mark H, Swift CD, Price RE, Rao PV (1972) X-ray fluorescence yields, Auger and Coster-Kronig transition probabilities. Rev Mod Phys 44 716-813 Bearden JA (1964) X-ray wavelengths. U. S. Atomic Energy Commission Report NY0-10586 Bearden JA (1967) X-ray wavelengths. Rev Mod Phys 39 78-124... 

Figure 22. Auger electron emission and X-ray fluorescence yields for K-shell electron vacancies as a function of atomic number. (From Ref. 69.)...

K-X ray fluorescent yield versus atomic number Z. In the case of iodine Z = 53 and fluorescent yield 88.2 %. 

Figure 11.9 shows the relative X-ray fluorescent yields as a function of atomic number. 

Figure 11.9 Relative X-ray Fluorescent Yields as a Function of Atomic Number of the...

At much the same time that TRBD was developed, another surface-sensitive X-ray technique was also reported. This relied on the well-known fact that the dynamical diffraction of an X-ray plane wave at a perfect crystal leads to the formation of an interference field on either side of the surface. As the angle of incidence is scanned through the Bragg angle, so this interference field moves. By monitoring the X-ray fluorescent yield as the beam is... 

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