Toward functionalized ultrathin oxide films: the impact of surface apical oxygen

DOI: 10.1002/aelm.202101006

Authors: Judith Gabel (Diamond Light Source) , Matthias Pickem (TU Wien) , Philipp Scheiderer (Universität Würzburg) , Lenart Dudy (Synchrotron SOLEIL) , Berengar Leikert (Universität Würzburg) , Marius Fuchs (Universität Würzburg) , Martin Stübinger (Universität Würzburg) , Matthias Schmitt (Universität Würzburg) , Julia Kuespert (Universität Würzburg) , Giorgio Sangiovanni (Universität Würzburg) , Jan M. Tomczak (TU Wien) , Karsten Held (TU Wien) , Tien-Lin Lee (Diamond Light Source) , Ralph Claessen (Universität Würzburg) , Michael Sing (Universität Würzburg)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Advanced Electronic Materials , VOL 102

State: Published (Approved)
Published: December 2021
Diamond Proposal Number(s): 23737 , 25151

Abstract: Thin films of transition metal oxides open up a gateway to nanoscale electronic devices beyond silicon characterized by novel electronic functionalities. While such films are commonly prepared in an oxygen atmosphere, they are typically considered to be ideally terminated with the stoichiometric composition. Using the prototypical correlated metal SrVO3 as an example, it is demonstrated that this idealized description overlooks an essential ingredient: oxygen adsorbing at the surface apical sites. The oxygen adatoms, which are present even if the films are kept in an ultrahigh vacuum environment and not explicitly exposed to air, are shown to severely affect the intrinsic electronic structure of a transition metal oxide film. Their presence leads to the formation of an electronically dead surface layer but also alters the band filling and the electron correlations in the thin films. These findings highlight that it is important to take into account surface apical oxygen or—mutatis mutandis—the specific oxygen configuration imposed by a capping layer to predict the behavior of ultrathin films of transition metal oxides near the single unit-cell limit.

Journal Keywords: correlated oxides; electronic phase transitions; photoelectron spectroscopy; thin films; transition metal oxides

Subject Areas: Materials, Physics


Instruments: I09-Surface and Interface Structural Analysis

Added On: 30/12/2021 10:10

Documents:
Adv Elect Materials - 2022 - Gabel - Toward Functionalized Ultrathin Oxide Films The Impact of Surface Apical Oxygen.pdf

Discipline Tags:

Surfaces Hard condensed matter - electronic properties Physics Hard condensed matter - structures Electronics Materials Science interfaces and thin films Nanoscience/Nanotechnology

Technical Tags:

Spectroscopy X-ray Photoelectron Spectroscopy (XPS) Hard X-ray Photoelectron Spectroscopy (HAXPES)