Room Temperature Interaction of Ultrathin-film Yttrium with SrTiO3(100) , LaAlO3(100) and MgO(100) surfaces

Jens Enevold Thaulov Andersen, Preben Juul Møller

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Abstract

The crystallographic and electronic structures of surfaces of the large-gap semiconductors SrTiO3(100) and LaAlO3(100), and of the insulator MgO (100), were followed during the initial stages of a metal-beam deposition of yttrium metal at room temperature. The techniques used are low-energy electron diffraction, Auger-, electron-energy-loss, and ultraviolet photoelectron spectroscopy. Yttrium grows epitaxially 1 x 1 on the MgO (100) surface and nonepitaxially on the LaAlO3(100) and SrTiO3(100) surfaces. Initially, below monolayer coverage, Y is strongly oxidized by the MgO(100) substrate. Near-monolayer yttrium coverages Y2+ is identified, and upon further Y deposition the oxidation state gradually changes further towards a lower value. Oxidation of an yttrium film on 1 x 1 MgO(100) results in changes around the Fermi level and changes in the core-level binding energies, but no changes in the upper valence band were observed.
Original languageEnglish
JournalPysical Review B
Volume44
Issue number24
Pages (from-to)13645-13654
ISSN0163-1829
DOIs
Publication statusPublished - 1991
Externally publishedYes

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