Heterogenous mixed-valence and compound formation in ordered Yb/Ni(100) overlayers

Journal Article · Tue Dec 15 04:00:00 EST 1987 · Phys. Rev. B: Condens. Matter; (United States)

DOI:https://doi.org/10.1103/PhysRevB.36.9308· OSTI ID:5683296

Nilsson, A; Eriksson, B; Martensson, N; Andersen, J N; Onsgaard, J

The Yb valence state for ordered Yb/Ni(100) overlayers has been studied by use of photoelectron spectroscopy. At coverages between 50% and 100% of a densely packed Yb layer a c(10 x 2) surface structure is seen. The ultraviolet photoemission spectroscopy spectrum for this situation reveals both divalent and trivalent 4f emission features, indicating a mixed-valent state. From the observed 4f binding energies it is concluded that the mixed valence is of a heterogenous nature. The results are interpreted in terms of the formation of an epitaxial surface intermetallic compound with Yb distributed over several atomic layers. The results demonstrate the importance of surface compound formation in the present type of systems and offers an alternative explanation to the homogenous mixed-valence recently proposed for related Sm overlayers.

• Research Organization: Department of Physics Uppsala University, Box 530, S-751 21 Uppsala, Sweden
• OSTI ID: 5683296
• Journal Information: Phys. Rev. B: Condens. Matter; (United States), Journal Name: Phys. Rev. B: Condens. Matter; (United States) Vol. 36:17; ISSN PRBMD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360104* -- Metals & Alloys-- Physical Properties
COATINGS
ELECTRON SPECTROSCOPY
ELECTRONIC STRUCTURE
ELEMENTS
METALS
NICKEL
PHOTOELECTRON SPECTROSCOPY
RARE EARTHS
SPECTROSCOPY
SURFACE PROPERTIES
TRANSITION ELEMENTS
VALENCE
YTTERBIUM