In-situ probing of coupled atomic restructuring and metallicity of oxide heterointerfaces induced by polar adsorbates
Abstract
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 LaAlO3/SrTiO3 (001) heterostructure is changed by polar adsorbates. We find that polar adsorbate-induced interfacial metallicity reduces polar distortions in the LaAlO3 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 LaAlO3 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. 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.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 02, 2017
- Source ID
- 10.1063/1.4991956
Entities
People
- C. B. Eom
- C. W. Bark
- D. D. Fong
- Dongjin Lee
- E. Y. Tsymbal
- Huibin Zhou
- Jacob Podkaminer
- Julian Irwin
- M. S. Rzchowski
- Sangwoo Ryu
- T. H. Kim
- T. R. Paudel
Organizations
- Air Force Office of Scientific Research
- Argonne National Laboratory
- Division of Materials Research
- United States Department of Energy
- University of Nebraska–Lincoln
- University of Wisconsin–Madison