Photon emission produced by Kr+ ions bombardment of Cr and Cr2O3 targets

• Published in: Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms Beam interactions with materials and atoms, 2015-01, Vol.343, p.158-162
• Main Authors: Boujlaidi, A. El, Hammoum, K., Jadoual, L., Jourdani, R., Ait El Fqih, M., Aouchiche, H., Kaddouri, A.
• Format: Article
• Language: English
• Subjects: Beam interactions; Chromium; Chromium oxide; Chromium oxides; Electron-transfer model; Excitation spectra; Ion bombardment; Oxides; Partial pressure; Photon emission; Photons; Sputtering
• ISSN: 0168-583X; 1872-9584
• DOI: 10.1016/j.nimb.2014.11.074

The sputter induced photon spectroscopy technique was used to study the luminescence spectra of the species sputtered from chromium powder and its oxide Cr2O3, during 5keV Kr+ ions bombardment in vacuum better than 10−7torr. The optical spectra recorded between 350 and 470nm exhibit discrete lines which are attributed to neutral excited atoms of chromium (Cr I lines). The experiments are also performed under 10−5torr ultra pure oxygen partial pressure. The results demonstrate that the measured intensities of the emitted photons are always higher in the presence of oxygen and even higher than those obtained for Cr2O3 target. In the presence of oxygen vapor we assume that an oxide film is formed on the chromium surface which is responsible of the increase of photon emission. This variation in the intensities is correctly explained in the model of electron transfer processes between the excited sputtered atom and the bombarded surface. This model suggests that the structure formed on the Cr surface in the case of oxygenated chromium is closer to that of Cr2O3 oxide.