TY - JOUR
T1 - Nanoscale Chemical and Valence Evolution at the Metal/Oxide Interface
T2 - A Case Study of Ti/SrTiO3
AU - Li, Yangyang
AU - Wang, Qingxiao
AU - An, Ming
AU - Li, Kun
AU - Wehbe, Nimer
AU - Zhang, Qiang
AU - Dong, Shuai
AU - Wu, Tom
N1 - Funding Information:
This work was supported by the King Abdullah University of Science and Technology (KAUST). M.A. and S.D. were supported by the National Natural Science Foundation (Grant No. 11274060). The experiments were performed in the Nanofabrication & Thin Film core lab, and the Imaging & Characterization Core Lab in KAUST.
Publisher Copyright:
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
PY - 2016/9/6
Y1 - 2016/9/6
N2 - Metal/oxide interfaces are ubiquitous in a wide range of applications such as electronics, photovoltaics, memories, catalysis, and sensors. However, there have been few investigations dedicated to the nanoscale structural and chemical characteristics of these buried interfaces. In this work, the metal/oxide interface between Ti and SrTiO3 (STO) is examined as a prototypical system using high-resolution scanning transmission electron microscopy and electron energy loss spectroscopy. An atomic-thin Ti2O3-like layer at the Ti/STO interface prepared at room temperature is discovered, and first-principles calculations predict a metallic band structure of this 2D electron system. As a universal feature of such interfaces prepared at different temperatures, near the interface nanoscale oxygen-deficient domains and continuous modulation of Ti oxidation states are found. Overall, these results directly reveal complex chemical and valence evolutions at the metal/oxide interfaces, providing microscopic insights on such heterostructures.
AB - Metal/oxide interfaces are ubiquitous in a wide range of applications such as electronics, photovoltaics, memories, catalysis, and sensors. However, there have been few investigations dedicated to the nanoscale structural and chemical characteristics of these buried interfaces. In this work, the metal/oxide interface between Ti and SrTiO3 (STO) is examined as a prototypical system using high-resolution scanning transmission electron microscopy and electron energy loss spectroscopy. An atomic-thin Ti2O3-like layer at the Ti/STO interface prepared at room temperature is discovered, and first-principles calculations predict a metallic band structure of this 2D electron system. As a universal feature of such interfaces prepared at different temperatures, near the interface nanoscale oxygen-deficient domains and continuous modulation of Ti oxidation states are found. Overall, these results directly reveal complex chemical and valence evolutions at the metal/oxide interfaces, providing microscopic insights on such heterostructures.
KW - SrTiO
KW - electron energy loss spectrum
KW - first-principles calculation
KW - interfaces
KW - oxygen vacancies
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U2 - 10.1002/admi.201600201
DO - 10.1002/admi.201600201
M3 - Article
AN - SCOPUS:84985916952
SN - 2196-7350
VL - 3
JO - Advanced Materials Interfaces
JF - Advanced Materials Interfaces
IS - 17
M1 - 1600201
ER -