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Time-Resolved Reflection High-Energy Electron Diffraction Study Of The Ge(111)-C(2×8)-(1×1) Phase Transition, Xinglin Zeng, Bo Lin, Ibrahim El-Kholy, Hani E. Elsayed-Ali
Time-Resolved Reflection High-Energy Electron Diffraction Study Of The Ge(111)-C(2×8)-(1×1) Phase Transition, Xinglin Zeng, Bo Lin, Ibrahim El-Kholy, Hani E. Elsayed-Ali
Electrical & Computer Engineering Faculty Publications
The dynamics of the Ge(111)-c(2×8)-(1×1) phase transition is investigated by 100-ps time-resolved reflection high-energy electron diffraction. A laser pulse heats the surface while a synchronized electron pulse is used to obtain the surface diffraction pattern. Slow heating shows that the adatoms in Ge(111)-c(2×8) start to disorder at ∼510 K and are converted to a disordered adatom arrangement at 573 K. For heating with 100-ps laser pulses, the Ge(111)-c(2×8) reconstructed adatom arrangement starts to disorder at 584±16K, well above the onset temperature of ∼510 K for the disordering of Ge(111)-c(2×8) observed for slow …
Réalisation De Couches Minces De Cualse² Par Recuit De Feuilllets Superposés Cu/Al/Se/Al…, Étude De Conditions De Dépôt, C.O. El Moctar, S. Marsillac, J. C. Bernede, A. Conan, K. Benchouk, A. Khelil
Réalisation De Couches Minces De Cualse² Par Recuit De Feuilllets Superposés Cu/Al/Se/Al…, Étude De Conditions De Dépôt, C.O. El Moctar, S. Marsillac, J. C. Bernede, A. Conan, K. Benchouk, A. Khelil
Electrical & Computer Engineering Faculty Publications
Thin layers of Cu/Al/Se/Al/Cu/Al/Se/…/Al/Se sequentially deposited have been annealed half an hour at 855 K. CuAlSe2 thin films crystallized in the chalcopyrite structure are obtained. The films being contaminated by oxygen, the experimental deposition conditions of the aluminum layer have been improved in order to decrease the atomic concentration of oxygen below 5 at%. Such results can be obtained in vacuum of 10-4 Pa, when the aluminum deposition rate is 1 nm/s and when the layer is immediately covered after deposition. Films obtained in such a way are nearly stoichiometric with lattice parameters in accordance with the expected …