Atomic and electronic structure of an unreconstructed polar MgO(111) thin film on Ag(111)

Abstract

Atomic and electronic structures of a polar surface of MgO formed on Ag(111) was investigated by using reflection high energy electron diffraction (RHEED), Auger electron spectroscopy, electron energy loss spectroscopy (EELS), and ultraviolet photoemission spectroscopy (UPS). A rather flat unreconstructed polar MgO(111) 1×1 surface could be grown by alternate adsorption of Mg and O2 on Ag(111). The stability of the MgO(111) surface was discussed in terms of interaction between Ag and Mg atoms at the interface, and charge state of the surface atoms. EELS of this surface did not show a band gap region, and finite density of states appeared at the Fermi level in UPS. These results suggest that a polar MgO(111) surface was not an insulating surface but a semiconducting or metallic surface.

Interplay between structural, magnetic, and electronic properties in aFeO∕Pt(111)ultrathin film

“…20,21 The situation is qualitatively different for ultra-thin films: rather flat, unreconstructed MgO(111) ultra-thin films have been successfully stabilized on Ag(111). 22,23 For these nano-structures the polarity may be compensated by a structural transformation. 24 The iron oxide on Pt(111), on the other hand, presents a non-vanishing Fe-O rumpling and therefore can be considered as a nano-system in which uncompensated polarity remains.…”

Metal-induced gap states in epitaxial organic-insulator/metal interfaces

“…4 However, recent developments in the molecular beam epitaxy ͑MBE͒ technique have made it possible to prepare various types of heterointerfaces. 8,9 Some organic films are in fact begun to be epitxially grown on metal substrates in a layer-by-layer fashion with MBE. 10 Given this background, the purpose of the present paper is to examine the interface states in an atomically well-defined organic insulator ͑an alkane; C 44 H 90 ͒ grown on Cu substrate.…”

Surface-interface exploration of Mg deposited on Si(100) and oxidation effect on interfacial layer

“…2 The main issue is to find new routes to process well controlled homogenous oxide layers on semiconductor surfaces known for their high reactivity to oxygen species, and more precisely on how to reach a high-quality interface between the deposit and the silicon substrate. 3-5 Some recent studies explore an innovating growth method, in which the oxidation is performed at room temperature (RT) on a metallic monolayer (ML) previously deposited on silver or silicon substrates [6][7][8][9][10][11] resulting in a high homogenous oxide layer, with sharp interfaces and preventing oxidation of the silicon substrate. To master this process, it is crucial to finely control and get a fundamental description with an atomic scale precision about the deposition of the metallic layer in direct contact with the substrate.…”