Abstract
Abstract
Chemical modifications such as intercalation can be used to modify surface properties or to further functionalize the surface states of topological insulators (TIs). Using ambient pressure x-ray photoelectron spectroscopy, we report copper migration in
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, which occurs on a timescale of hours to days after initial surface cleaving. The increase in near-surface copper proceeds along with the oxidation of the sample surface and large changes in the selenium content. These complex changes are further modeled with core-level spectroscopy simulations, which suggest a composition gradient near the surface which develops with oxygen exposure. Our results shed light on a new phenomenon that must be considered for intercalated TIs—and intercalated materials in general—that surface chemical composition can change when specimens are exposed to ambient conditions.
Funder
U.S. Department of Energy
Alfred P. Sloan Foundation
National Science Foundation
University of California Lab Fees
Air Force Office of Scientific Research
Subject
Condensed Matter Physics,General Materials Science,Atomic and Molecular Physics, and Optics
Cited by
2 articles.
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