Sm- and Yb-induced reconstructions of the Si(111) surface
1993 (English)In: Physical Review B, ISSN 01631829 (ISSN), Vol. 48, no 15, 11014-11019 p.Article in journal (Refereed) Published
Low-energy electron diffraction, scanning tunneling microscopy, and photoelectron spectroscopy results from the submonolayer Sm- and Yb-induced surface structures are presented. Several similar metal-induced surface reconstructions are found to exist for Yb and Sm on Si(111) for low submonolayer coverages: 3Ã—2, 5Ã—1, and 7Ã—1. At higher submonolayer coverage, Yb induces a 2Ã—1 reconstruction while Sm induces a (3 Ã— 3) R30Â°-like reconstruction. Yb is found to be divalent in all structures, whereas the Sm valence increases with increasing coverage. In the 3Ã—2 structure only divalent Sm is present, in the 5Ã—1 and 7Ã—1 structures a small amount of trivalent Sm appears, and, finally, in the (3 Ã— 3) R30Â°structure approximately half of the Sm atoms are trivalent. The surface Fermi-level position in the band gap for the different Sm and Yb reconstructions has been measured. The difference in valence stability between Sm and Yb is suggested to be the cause of the difference in the high-coverage structures found and the differences in pinning level for the two elements observed for the 5Ã—1 and 7Ã—1 structures. Â© 1993 The American Physical Society.
Place, publisher, year, edition, pages
1993. Vol. 48, no 15, 11014-11019 p.
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:kth:diva-83043DOI: 10.1103/PhysRevB.48.11014OAI: oai:DiVA.org:kth-83043DiVA: diva2:498711
Correspondence Address: Wigren, C.; Department of Synchrotron Radiation Research, Institute of Physics, Lund University, SÃ¶lvegatan 14, S-223 62 Lund, Sweden NR 201408052012-02-122012-02-122012-02-12Bibliographically approved