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Electronic structure of self‐assembled Sm nanostructure on HOPG studied by in‐situ photoemission spectroscopy and scanning probe microscopy
Author(s) -
Kutluk G.,
Nakatake M.,
Sumuda H.,
Namatame H.,
Taniguchi M.
Publication year - 2010
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.3470
Subject(s) - nanostructure , in situ , materials science , photoemission spectroscopy , scanning probe microscopy , spectroscopy , microscopy , scanning tunneling microscope , nanotechnology , photoemission electron microscopy , x ray photoelectron spectroscopy , crystallography , analytical chemistry (journal) , chemistry , nuclear magnetic resonance , physics , optics , electron microscope , organic chemistry , quantum mechanics , chromatography
Abstract In‐situ photoemission spectroscopy of Sm over‐layer on HOPG in the coverage regime of 0.3∼10.0 Å has been performed at room temperature in the 4d–4f resonance energy region by using monochromatic synchrotron radiation light. Based on analysis of the spectra taken at hν = 134 eV (close to divalent samarium resonance), it is indicated that the divalent feature predominates the valence band spectra for the coverage below than 1.0 Å, while the trivalent structures are enhanced for Sm over‐layer coverage higher than the 1.0 Å. However, in the case of valence band spectra are excited with the photon of energy of 141 eV at trivalent samarium resonance, the trivalent feature dominates the spectra across over the 0.6∼10.0 Å coverage of Sm over‐layer. The mixed valence in the present Sm over‐layer system might be heterogeneous in nature. Our first result indicates that the VUV irradiation of Sm makes an important role for stimulating the degeneration of divalent multi‐configuration during the vacuum ultraviolet photoemission spectroscopy. Copyright © 2010 John Wiley & Sons, Ltd.