Medium-energy ion scattering studies of two-dimensional rare-earth silicides

Abstract

Medium-energy ion scattering ͑MEIS͒ has been used to determine the atomic structure of two-dimensional ͑2D͒ rare-earth silicides on Si͑111͒. In the case of the Si͑111͒1ϫ1-Er 2D silicide surface, the MEIS results refine previously published results, but in the case of the Si͑111͒1ϫ1-Ho surface, this work represents to our knowledge the first full quantitative structural analysis that reveals a structure similar to that of the Si͑111͒1 ϫ1-Er surface and directly supports a model in which a rare-earth monolayer resides below a Si bilayer close to bulklike termination.

Electronic structure and Fermi surface of two-dimensional rare-earth silicides epitaxially grown on Si(111)

“…1 and only small differences in the atomic layer distances have been reported between them. [12][13][14][15][16] In this work we show that the electronic structures of YSi 2 , GdSi 2 , and ErSi 2 are coincident too. Their respective ARUPS spectra and FSs can be overimposed without noticeable difference.…”

“…[7][8][9] In contrast to the bulk, this phase does not include Si vacancies and therefore the film presents a RESi 2 stoichiometry. The atomic structure of the two-dimensional phase was first reported for Si(111)ϩ p(1ϫ1)-ErSi 2 , 10,11 and recently, the same model was proposed for other heavy RE silicides, such as Y, Dy, and Ho silicides [12][13][14][15][16] and germanides. 17 The geometry consists of an interfacial RE layer positioned at T 4 sites and with a Si bilayer on top.…”

Holmium growth on Si(001): Surface reconstructions and nanowire formation

“…4 This nanowire formation is ascribed to good lattice match in one direction and bad lattice match in the perpendicular direction. 3,4 Although a few structural studies of Ho on Si͑111͒ have been done, 5,6 there has been no investigation in Ho on Si͑001͒ surface yet. In this work we present a scanning tunneling microscopy ͑STM͒ and scanning tunneling spectroscopy ͑STS͒ study of Ho growth on Si͑001͒.…”

Role of step roughening in the formation of Ce silicide on Si(111)

“…Fundamental aspects of rareearth silicides such as the formation of silicide and reconstruction with various coverages at different annealing temperatures due to their relatively low Schottky-barrier heights (0.15-0.40 eV) on n-type Si [1] has drawn a lot of attention. The formation of silicide with various surface properties has been reported in systems involving Ce [2], Sm [3], Er [4], Eu [5], and Gd [6]. However, most of this work has focused only on surface reactions occurring at terraces on the Si surface.…”