Preparation and characterization of Bi2Se3(0001) and of epitaxial FeSe nanocrystals on Bi2Se3(0001)
| Autor: | Sujit Manna, Vasilii Sevriuk, Dirk Sander, Jürgen Kirschner, S. Ouazi, A. Cavallin, Christian Tusche, Martin Ellguth, Kenia Novakoski Fischer, Holger L. Meyerheim |
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| Rok vydání: | 2016 |
| Předmět: |
Materials science
Photoemission spectroscopy Annealing (metallurgy) Cleavage (crystal) 02 engineering and technology Surfaces and Interfaces 021001 nanoscience & nanotechnology Condensed Matter Physics Epitaxy 01 natural sciences Surfaces Coatings and Films law.invention Crystallography chemistry.chemical_compound Nanocrystal Electron diffraction chemistry law 0103 physical sciences Materials Chemistry Bismuth selenide Scanning tunneling microscope 010306 general physics 0210 nano-technology |
| Zdroj: | Surface Science. 646:72-82 |
| ISSN: | 0039-6028 |
| DOI: | 10.1016/j.susc.2015.09.001 |
| Popis: | Procedures to prepare clean Bi2Se3(0001) surfaces from bulk samples and epitaxial FeSe nanocrystals on Bi2Se3(0001) are reported. Bi2Se3(0001) substrates are prepared by in vacuo cleavage of bulk samples, followed by ion bombardment and annealing cycles. FeSe is prepared by Fe deposition onto Bi2Se3 at 303 K, followed by annealing at T ≈ 623 K. We use low-energy electron diffraction, surface X-ray diffraction, photoemission spectroscopy, scanning tunneling microscopy and spectroscopy, and stress measurements to elucidate the correlation between structural and electronic properties of the pristine Bi2Se3(0001) and FeSe covered surfaces. Our analysis reveals the formation of epitaxial FeSe nanocrystals with a thickness of three unit cells (1.5 nm). Electron diffraction experiments indicate an anisotropic epitaxial strain in FeSe. A negligible strain close to 0.0% and a tensile strain of + 2.1% are observed along the in-plane 01 1 ¯ 0 and 2 11 ¯ 0 Bi2Se3 directions, respectively. The out-of-plane strain is + 4.2%. The role of this strain state for the reported high-TC superconductivity in bulk FeSe is discussed. |
| Databáze: | OpenAIRE |
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