Pb/NiSi[formula omitted] atomic sandwich on Si(111)

Abstract

Atomic sandwich consisting of single atomic layers of Pb and NiSi2 has been grown on Si(111) and its structural, electronic and transport properties have been elucidated using a set of experimental techniques, scanning tunneling microscopy, angle-resolved photoelectron spectroscopy, in situtransport and magnetotransport measurements, and density functional theory calculations. The Pb layers incorporate around 1.1 monolayers of Pb and display a melt-like 1 × 1 structure at room temperature which crystallizes into the 7 × 7-R38.2∘ (i.e., (83−35)) and “21×39” (i.e., (4−157)) structures upon cooling to low temperatures. Electronic band structure of the Pb/NiSi2/Si(111) sandwich contains two bands associated with NiSi2 and two spin-split bands associated with Pb with minor hybridization of the electrons belonging to different layers. Concerning the transport properties at low temperatures, the sandwich demonstrates a high conductance but without clear indication on superconductivity.