| AVS 64th International Symposium & Exhibition | |
| Applied Surface Science Division | Tuesday Sessions |
| Session AS+MI+SS-TuM |
| Session: | Quantitative Surface Analysis: Effective Quantitation Strategies |
| Presenter: | Jorge-Alejandro Torres-Ochoa, CINVESTAV-Unidad Queretaro, Mexico |
| Authors: | J.A. Torres-Ochoa, CINVESTAV-Unidad Queretaro, Mexico D. Cabrera-German, Universidad de Sonora, Mexico M. Bravo-Sanchez, Instituto Potosino de Investigación Científica y Tecnológica A.C, Mexico A. Herrera-Gomez, CINVESTAV-Unidad Queretaro, Mexico |
| Correspondent: | Click to Email |
Some X-ray photoelectron spectra have complicated structures that makes the peak fitting procedure difficult, especially with transition metals. Recent studies have shown the need to fit both branches of the 2p spectra such as in Fe 1 and Co 2 This proved that modeling both branches concurrently is necessary to avoid errors such as area underestimation. In this report, copper films were obtained by sublimation in ultra-high vacuum (5.5x10‑8 torr) on Si(100) substrates. Immediately after deposition, the films were characterized by X-ray photoelectron spectroscopy using a monochromatic Al Kα source (hv=1486.7 eV). To study the initial stages of oxidation, the films were heat treated in an ultra-high purity oxygen atmosphere at 200 °C from 1 to 10 min.
From the photoemission spectrum, it was possible to observe three coexisting copper species. Using the Active Background Method,3 an accurate fit was achieved for Cu 2p. Both chemical species, Cu1+ (932.5 eV) and Cu2+ (933.5 eV), together with their satellites (Cu1+: 946.5 eV, Cu2+: 941.1 eV, and Cu2+; 943.9 eV) were clearly identified.4 The fit required two extra peaks at 934.7 eV and 942.4 eV. There is evidence that these peaks correspond to Cu3+.
References
1. Bravo Sanchez, M., Huerta-Ruelas, J. A., Cabrera-German, D. & Herrera-Gomez, A. Composition assessment of ferric oxide by accurate peak fitting of the Fe 2p photoemission spectrum. Surf. Interface Anal. (2016). doi:10.1002/sia.6124
2. Cabrera-German, D., Gomez-Sosa, G. & Herrera-Gomez, A. Accurate peak fitting and subsequent quantitative composition analysis of the spectrum of Co 2p obtained with Al K α radiation: I: cobalt spinel. Surf. Interface Anal.48, 252–256 (2016).
3. Herrera-Gomez, A., Bravo-Sanchez, M., Ceballos-Sanchez, O. & Vazquez-Lepe, M. O. Practical methods for background subtraction in photoemission spectra. Surf. Interface Anal.46, 897–905 (2014).
4. Pauly, N., Tougaard, S. & Yubero, F. Determination of the Cu 2p primary excitation spectra for Cu, Cu 2O and CuO. Surf. Sci.620, 17–22 (2014).