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Title: In-situ probing of coupled atomic restructuring and metallicity of oxide heterointerfaces induced by polar adsorbates

Microscopic understanding of the surface-controlled conductivity of the two dimensional electron gas at complex oxide interfaces is crucial for developing functional interfaces. We observe conductivity and structural modification using in-situ synchrotron surface x-ray diffraction as the surface of a model LaAlO 3/SrTiO 3 (001) heterostructure is changed by polar adsorbates. We find that polar adsorbate-induced interfacial metallicity reduces polar distortions in the LaAlO 3 layer. First-principles density functional theory calculations show that surface dipoles introduced by polar adsorbates lead to additional charge transfer and the reduction of polar displacements in the LaAlO 3 layer, consistent with the experimental observations. Our study supports that internal structural deformations controlling functionalities can be driven without the application of direct electrical or thermal bias and offers a route to tuning interfacial properties. Furthermore, these results also highlight the important role of in-situ x-ray scattering with atomic resolution in capturing and exploring structural distortions and charge density changes caused by external perturbations such as chemical adsorption, redox reaction, and generation and/or annihilation of surface defects.
Authors:
ORCiD logo [1] ;  [2] ;  [3] ; ORCiD logo [1] ; ORCiD logo [1] ;  [1] ;  [1] ;  [1] ;  [2] ;  [1] ;  [3] ;  [1]
  1. Univ. of Wisconsin-Madison, Madison, WI (United States)
  2. Argonne National Lab. (ANL), Argonne, IL (United States)
  3. Univ. of Nebraska, Lincoln, NE (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357; FG02-06ER46327
Type:
Accepted Manuscript
Journal Name:
Applied Physics Letters
Additional Journal Information:
Journal Volume: 111; Journal Issue: 14; Journal ID: ISSN 0003-6951
Publisher:
American Institute of Physics (AIP)
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
National Science Foundation (NSF); Air Force Research Laboratory (AFRL), Air Force Office of Scientific Research (AFOSR); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22). Materials Sciences & Engineering Division; USDOE
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; Adsorption; Chemical compounds; Heterointerfaces; Heterojunctions; Synchrotrons
OSTI Identifier:
1418361
Alternate Identifier(s):
OSTI ID: 1396065