Experimental and density functional study of Mn doped Bi2Te3 topological insulator

Abstract

We present a nanoscale structural and density functional study of the Mn doped 3D topological insulator Bi2Te3. X-ray absorption near edge structure show that Mn has valency of nominally 2+. Extended x-ray absorption fine structure spectroscopy in combination with electron energy loss spectroscopy (EELS) shows that Mn is a substitutional dopant of Bi and Te and also resides in the van der Waals gap between the quintuple layers of Bi2Te3. Combination of aberration-corrected scanning transmission electron microscopy and EELS show that Mn substitution of Te occurs in film regions with increased Mn concentration. First-principles calculations show that the Mn dopants favor octahedral sites and are ferromagnetically coupled.

Metadata

Item Type:

Article

Authors/Creators:

Ghasemi, Arsham
Kepaptsoglou, D
Figueroa, A. I.
Naydenov, Genadi Antonov (gan503@york.ac.uk)
Hasnip, Philip James https://orcid.org/0000-0002-4314-4093
Probert, Matthew Ian James https://orcid.org/0000-0002-1130-9316
Ramasse, Q
van der Laan, G
Hesjedal, T
Lazarov, Vlado https://orcid.org/0000-0002-4314-6865

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Keywords:

DFT, density functional theory, topological insulators

Dates: