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Title: Stoichiometry dependence of potential screening at La ( 1 - δ ) Al ( 1 + δ ) O 3 / SrTiO 3 interfaces

Abstract

Hard x-ray photoelectron spectroscopy (HAXPES) and variable kinetic energy x-ray photoelectron spectroscopy (VKE-XPS) analyses have been performed on ten-unit-cell-thick La (1-δ)Al (1+δ)O₃ films, with La:Al ratios of 1.1, 1.0, and 0.9, deposited on SrTiO₃. Only Al-rich films are known to have a conductive interface. VKE-XPS, coupled with maximum entropy analysis, shows significant differences in the compositional depth profile among the Al-rich, La-rich, and stoichiometric films: significant La enrichment at the interface is observed in the La-rich and stoichiometric films, while the Al-rich film shows little to no intermixing. Additionally, the La-rich and stoichiometric films show a high concentration of Al at the surface, which is not observed in the Al-rich film. HAXPES valence band (VB) analysis shows a broadening of the VB for the Al-rich sample relative to the stoichiometric and La-rich samples. This broadening is consistent with an electric field across the Al-rich film. These results are consistent with a defect-driven electronic reconstruction.

Authors:
; ; ; ; ; ;
Publication Date:
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1177475
Grant/Contract Number:  
AC02-98CH10886
Resource Type:
Publisher's Accepted Manuscript
Journal Name:
Physical Review. B, Condensed Matter and Materials Physics
Additional Journal Information:
Journal Name: Physical Review. B, Condensed Matter and Materials Physics Journal Volume: 91 Journal Issue: 16; Journal ID: ISSN 1098-0121
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE

Citation Formats

Weiland, Conan, Sterbinsky, George E., Rumaiz, Abdul K., Hellberg, C. Stephen, Woicik, Joseph C., Zhu, Shaobo, and Schlom, Darrell G.. Stoichiometry dependence of potential screening at La ( 1 - δ ) Al ( 1 + δ ) O 3 / SrTiO 3 interfaces. United States: N. p., 2015. Web. doi:10.1103/PhysRevB.91.165103.
Weiland, Conan, Sterbinsky, George E., Rumaiz, Abdul K., Hellberg, C. Stephen, Woicik, Joseph C., Zhu, Shaobo, & Schlom, Darrell G.. Stoichiometry dependence of potential screening at La ( 1 - δ ) Al ( 1 + δ ) O 3 / SrTiO 3 interfaces. United States. doi:10.1103/PhysRevB.91.165103.
Weiland, Conan, Sterbinsky, George E., Rumaiz, Abdul K., Hellberg, C. Stephen, Woicik, Joseph C., Zhu, Shaobo, and Schlom, Darrell G.. Fri . "Stoichiometry dependence of potential screening at La ( 1 - δ ) Al ( 1 + δ ) O 3 / SrTiO 3 interfaces". United States. doi:10.1103/PhysRevB.91.165103.
@article{osti_1177475,
title = {Stoichiometry dependence of potential screening at La ( 1 - δ ) Al ( 1 + δ ) O 3 / SrTiO 3 interfaces},
author = {Weiland, Conan and Sterbinsky, George E. and Rumaiz, Abdul K. and Hellberg, C. Stephen and Woicik, Joseph C. and Zhu, Shaobo and Schlom, Darrell G.},
abstractNote = {Hard x-ray photoelectron spectroscopy (HAXPES) and variable kinetic energy x-ray photoelectron spectroscopy (VKE-XPS) analyses have been performed on ten-unit-cell-thick La(1-δ)Al(1+δ)O₃ films, with La:Al ratios of 1.1, 1.0, and 0.9, deposited on SrTiO₃. Only Al-rich films are known to have a conductive interface. VKE-XPS, coupled with maximum entropy analysis, shows significant differences in the compositional depth profile among the Al-rich, La-rich, and stoichiometric films: significant La enrichment at the interface is observed in the La-rich and stoichiometric films, while the Al-rich film shows little to no intermixing. Additionally, the La-rich and stoichiometric films show a high concentration of Al at the surface, which is not observed in the Al-rich film. HAXPES valence band (VB) analysis shows a broadening of the VB for the Al-rich sample relative to the stoichiometric and La-rich samples. This broadening is consistent with an electric field across the Al-rich film. These results are consistent with a defect-driven electronic reconstruction.},
doi = {10.1103/PhysRevB.91.165103},
journal = {Physical Review. B, Condensed Matter and Materials Physics},
number = 16,
volume = 91,
place = {United States},
year = {2015},
month = {4}
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record
DOI: 10.1103/PhysRevB.91.165103

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Cited by: 4 works
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