The Behavior of Na on 1x1 and 7x7 Structures of Si(111) and Its Effect on the Oxidation of These Structures
Φόρτωση...
Ημερομηνία
Συγγραφείς
Papageorgopoulos, C.
Kamaratos, M.
Τίτλος Εφημερίδας
Περιοδικό ISSN
Τίτλος τόμου
Εκδότης
Περίληψη
Τύπος
Είδος δημοσίευσης σε συνέδριο
Είδος περιοδικού
peer reviewed
Είδος εκπαιδευτικού υλικού
Όνομα συνεδρίου
Όνομα περιοδικού
Journal of Physics-Condensed Matter
Όνομα βιβλίου
Σειρά βιβλίου
Έκδοση βιβλίου
Συμπληρωματικός/δευτερεύων τίτλος
Περιγραφή
Deposition of Na on 1 x 1 and 7 x 7 structures of Si(111) at room temperature (RT) forms a uniform layer with a rather weak metallic character. The coverage of Na can be determined at any time of the Na deposition by a flux meter. The binding energy of Na is greater on a reconstructed 7 x 7 than on the 1 x 1 structure of a Si(111) surface. The initial dipole moment and the maximum DELTA-phi are greater for Na on the 1 x 1 structure. Near saturation Na coverage, the oxygen goes initially under the Na layer forming a Na-O-Si complex and subsequently resides on top of it. The presence of Na on Si(111) causes a drastic increase of the initial sticking coefficient of oxygen by about ten times. When oxygen is adsorbed on Na-covered Si(111) surfaces at RT and the system is heated to 700-degrees-C. Na is removed from the surface while oxygen forms SiO4 and SiO2. By repeating this cycle several times (seven) SiO2 predominates and its average thickness is about 9 angstrom. However, this thickness is smaller than when Cs is used instead of Na. This indicates that Cs is more effective as a promoter of the oxidation. However, the oxide formation occurs at a lower temperature than with Cs additives. Finally, the effect of Na on the oxidation of Si was almost the same on the 7 x 7 and 1 x 1 structures of Si(111) surfaces.
Περιγραφή
Λέξεις-κλειδιά
catalytic-oxidation, alkali-metals, cs, adsorption, surfaces, coadsorption, si(100), mos2, o-2
Θεματική κατηγορία
Παραπομπή
Σύνδεσμος
<Go to ISI>://A1992HF56100009
http://iopscience.iop.org/0953-8984/4/8/009/pdf/0953-8984_4_8_009.pdf
http://iopscience.iop.org/0953-8984/4/8/009/pdf/0953-8984_4_8_009.pdf
Γλώσσα
en
Εκδίδον τμήμα/τομέας
Όνομα επιβλέποντος
Εξεταστική επιτροπή
Γενική Περιγραφή / Σχόλια
Ίδρυμα και Σχολή/Τμήμα του υποβάλλοντος
Πανεπιστήμιο Ιωαννίνων. Σχολή Επιστημών και Τεχνολογιών. Τμήμα Βιολογικών Εφαρμογών και Τεχνολογιών