Realization of Epitaxial Thin Films of the Topological Crystalline Insulator Sr3 SnO

Yanjun Ma; Anthony Edgeton; Hanjong Paik; Brendan D Faeth; Christopher T Parzyck; Betül Pamuk; Shun-Li Shang; Zi-Kui Liu; Kyle M Shen; Darrell G Schlom; Chang-Beom Eom

doi:10.1002/adma.202000809

Realization of Epitaxial Thin Films of the Topological Crystalline Insulator Sr₃ SnO

Adv Mater. 2020 Aug;32(34):e2000809. doi: 10.1002/adma.202000809. Epub 2020 Jul 14.

Authors

Yanjun Ma^{1

2}, Anthony Edgeton², Hanjong Paik³, Brendan D Faeth⁴, Christopher T Parzyck⁴, Betül Pamuk³, Shun-Li Shang⁵, Zi-Kui Liu⁵, Kyle M Shen^{4

6}, Darrell G Schlom^{6

7

8}, Chang-Beom Eom²

Affiliations

¹ Department of Physics and Astronomy, West Virginia University, Morgantown, WV, 26506, USA.
² Department of Material Science and Engineering, University of Wisconsin-Madison, Madison, WI, 53706, USA.
³ Platform for the Accelerated Realization, Analysis, and Discovery of Interface Materials (PARADIM), Cornell University, Ithaca, NY, 14853, USA.
⁴ Laboratory of Atomic and Solid State Physics, Cornell University, Ithaca, NY, 14853, USA.
⁵ Department of Materials Science and Engineering, The Pennsylvania State University, University Park, Pennsylvania, PA, 16802, USA.
⁶ Kavli Institute at Cornell for Nanoscale Science, Ithaca, NY, 14853, USA.
⁷ Department of Material Science and Engineering, Cornell University, Ithaca, NY, 14853, USA.
⁸ Leibniz-Institut für Kristallzüchtung, Max-Born-Str. 2, Berlin, 12489, Germany.

PMID: 32666563
DOI: 10.1002/adma.202000809

Abstract

Topological materials are derived from the interplay between symmetry and topology. Advances in topological band theories have led to the prediction that the antiperovskite oxide Sr₃ SnO is a topological crystalline insulator, a new electronic phase of matter where the conductivity in its (001) crystallographic planes is protected by crystallographic point group symmetries. Realization of this material, however, is challenging. Guided by thermodynamic calculations, a deposition approach is designed and implemented to achieve the adsorption-controlled growth of epitaxial Sr₃ SnO single-crystal films by molecular-beam epitaxy (MBE). In situ transport and angle-resolved photoemission spectroscopy measurements reveal the metallic and electronic structure of the as-grown samples. Compared with conventional MBE, the used synthesis route results in superior sample quality and is readily adapted to other topological systems with antiperovskite structures. The successful realization of thin films of Sr₃ SnO opens opportunities to manipulate topological states by tuning symmetries via strain engineering and heterostructuring.

Keywords: angle-resolved photoemission spectroscopy; molecular beam epitaxy; topological crystalline insulators.

Abstract

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