AVS 65th International Symposium & Exhibition
    Novel Trends in Synchrotron and FEL-Based Analysis Focus Topic Wednesday Sessions
       Session SA+AS+MI-WeA

Paper SA+AS+MI-WeA12
Surface/Interface Coupling in Buried Oxide Interfaces

Wednesday, October 24, 2018, 6:00 pm, Room 202A

Session: Hard X-Ray Photoemission for Probing Buried Interfaces
Presenter: Conan Weiland, National Institute of Standards and Technology (NIST)
Authors: C. Weiland, National Institute of Standards and Technology (NIST)
A.K. Rumaiz, Brookhaven National Laboratory
G.E. Sterbinsky, Argonne National Laboratory
J.C. Woicik, National Institute of Standards and Technology (NIST)
Correspondent: Click to Email
Oxide interfaces can host a variety of properties not found in the bulk materials. The interface between LaAlO3 (LAO) and SrTiO3 (STO) is a prototypical example; the interface of these two insulators can show conductivity, ferromagnetism, and even superconductivity. The source of these interface properties is still a matter of debate, with potential explanations including electronic reconstruction due to the polar discontinuity at the interface, chemical intermixing, and oxygen vacancies at either the interface or LAO surface. Hard x-ray photoelectron spectroscopy (HAXPES) is an excellent tool to probe these interfaces due to the enhanced and tunable probe depth afforded by a synchrotron source. We have used a combination of variable kinetic energy HAXPES and ambient pressure soft x-ray photoelectron spectroscopy (AP-XPS) to investigate the interplay between LAO film and surface structure and the LAO/STO interface. We find Al surface enrichment for most LAO films, while AP-XPS shows significant band shifts in the presence of water vapor. The role of these LAO surface features on the LAO/STO interface conductivity will be discussed.