Surface electronic structure of two- and three-dimensional holmium silicide on Si(111)

Abstract

The surface electronic structure of two-and three-dimensional Ho silicides grown on Si͑111͒ has been studied with the techniques of metastable de-excitation spectroscopy ͑MDS͒ and ultraviolet photoemission spectroscopy. Electronic structure differences between the two cases are examined, and the extreme sensitivity of MDS to the surface density of states ͑DOS͒ allows a direct comparison between deconvolved spectra and ab initio density-functional theory calculations. This comparison shows a good agreement between the DOS calculated for the Si͑111͒-1 ϫ 1-Ho structure and MDS data obtained from an almost-complete layer of twodimensional Ho silicide. The dominant role of the topmost silicon bilayer in determining the surface electronic properties is revealed.

Structural and Chemical Properties of Gold Rare Earth Disilicide Core−Shell Nanowires

“…Bulk YSi 2 has an identical crystal structure of hexagonal RESi 2 , and their lattice constants are also similar. Many previous publications have demonstrated the appropriateness of using Y as a RE substitute for theoretical studies of atomic geometries and chemical properties of these systems. − The adsorption patterns of Y on Si(001) , and the morphology of YSi 2 nanowires on Si(001) have been analyzed recently using DFT calculations and SPM measurements. In particular, DFT predicted that YSi 2 nanowires with a width of 3a Si are the thinnest stable configuration on Si(001), in agreement with experimental observations for both YSi 2 and RESi 2 nanowires.…”

Characterizing ferromagnetic oxide/organic semiconductor interfaces using a spin-polarized metastable helium beam

“…Here, we briefly demonstrate how the use of a spin-polarized beam of metastable helium (He 2 3 S) atoms may provide complementary information to UPS but with a much greater surface sensitivity ( Fig. 1) 8), 9) . This sensitivity arises from the large surface interaction cross-section of He 2 3 S which means that deexcitation takes place several angstroms above the outermost surface.…”