| AVS 66th International Symposium & Exhibition | |
| Applied Surface Science Division | Tuesday Sessions |
| Session AS+BI+CA+LS-TuA |
| Session: | Beyond Traditional Surface Analysis |
| Presenter: | Germán Rafael Castro, Spanich CRG BM25-SpLine Beamline at the ESRF, France |
| Authors: | G.R. Castro, Spanich CRG BM25-SpLine Beamline at the ESRF, France J. Rubio Zuazo, Spanich CRG BM25-SpLine Beamline at the ESRF, France |
| Correspondent: | Click to Email |
Hard X-ray Photo-electron spectroscopy (HAXPES)[1] has been developed in the last 10-15 years as a unique tool for retrieving accurate non-destructive[2] compositional and electronic bulk property of materials in the tens of nano-meters depth-scale with nano-meter resolution. Furthermore, the ability to tune the excitation energy in the hard X-ray regime enables tuning the sampling depth, i.e. depth profile analysis, but also enables the discrimination between bulk and surface effects, especially if combined with variable incident and exit angle.
However, an important drawback is the lack of knowledge of the photo-ionization cross-section at the HAXPES photon energy and in special for now accessible deeper core levels. Recently theoretical data has been reported [6] concerning the photo-ionization cross sections and parameters of the photo-electron angular distribution for atomic subshells but for binding energies lower than 1.5 keV of all elements with 1≤ Z ≤ 100 in the photon energy range 1.5–10 keV. Unfortunately, these calculations do not contain information for deep orbitals accessible in HAXPES, even more there are scarce experimental results reported for both depth core levels and hard x-ray excitation energies.[3,4]
In the present work we will show the experimentally obtained relative sub-shell photo-ionization cross sections for 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4d, 4f, 5s, 5p, 5d core levels of gold (Au), 2s, 2p, 3s, 3p, 3d, 4s, 4p, 4d core levels of silver (Ag) and 1s, 2s, 2p, 3s, 3p, 3d core levels of Cooper (Cu) in the X-ray photon energy range of 7–26 keV. In the case of Au, cross sections have been corrected with experimental obtained angular anisotropy parameter. A comparison with theoretical sub-shell photo-ionization cross sections, and angular anisotropy photo-inionization parameters [5,6] will be also presented.
References
1. J. Rubio-Zuazo, G.R. Castro, Nucl. Instrum. Methods Phys. Res. A, 547, 64-72 (2005).
2. J. Rubio-Zuazo, P. Ferrer, G.R. Castro, J. Electron Spectrosc. Relat. Phenom., 180, 27-33 (2010).
3. M. Gorgoi, F.Schäfers, S.Svensson, N.Mårtensson,” J. Electron Spectrosc. Relat. Phenom.,, 190, 153-158 (2013)
4. C. Kunz, S. Thiess, B. Cowie, T.-L. Lee, J. Zegenhagen, Instrum. Methods Phys. Res. A, 547, 73-86 (2005).
5. J.H. Scofield, J. Electron Spectrosc. Relat. Phenom. 8 129–137 (1976).
6. M.B. Trzhaskovskaya, and V.G. Yarzhemsky, At. Data and Nucl. Data Tables,119 (2018) 99–174