Local Structure and Bonding of Transition Metal Dopants in Bi2Se3 Topological Insulator Thin Films
| Autor: | L. J. Collins-McIntyre, Giannantonio Cibin, Thorsten Hesjedal, Andrew J. Dent, Gerrit van der Laan, Adriana I. Figueroa |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Materials science
Spintronics Dopant Condensed matter physics Doping Surfaces Coatings and Films Electronic Optical and Magnetic Materials X-ray absorption fine structure Crystallography General Energy Transition metal Topological insulator Physical and Theoretical Chemistry Thin film Molecular beam epitaxy |
| Zdroj: | The Journal of Physical Chemistry C. 119:17344-17351 |
| ISSN: | 1932-7455 1932-7447 |
| DOI: | 10.1021/jp511713s |
| Popis: | Transition metal (TM) doped topological insulators have been the focus of many recent studies since they exhibit exotic quantum and magneto-electric effects, and offer the prospect of potential applications in spintronic devices. Here we report a systematic study of the local electronic and structural environment using X-ray absorption fine structure (XAFS) in TM (=Cr, Mn, and Fe) doped Bi2Se3 thin films grown by molecular beam epitaxy. Analysis of the TM K-edge XAFS reveals a divalent character for Cr, Mn, and Fe when substituting Bi in the films, despite the trivalent character of the Bi. All dopants occupy octahedral sites in the Bi2Se3 lattice, which agrees with substitutional incorporation onto the Bi sites. With the incorporation of TM dopants a local structural relaxation of the Bi2Se3 lattice is observed, which strengthens the covalent character of the TM–Se bond. The presence of additional phases and interstitial incorporation for the Mn and Fe dopants is also observed, even at low concentrations. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|