Observation of Distinct Bulk and Surface Chemical Environments in a Topological Insulator under Magnetic Doping

Ivana Vobornik (1) , Giancarlo Panaccione (1) , Jun Fujii (1) , Zhi-Huai Zhu (2) , Francesco Offi (1) , Benjamin R. Salles (1) , Francesco Borgatti (1) , Piero Torelli (1) , Jean Pascal Rueff (3, 4) , Denis Ceolin (3) , Alberto Artioli (1) , Manju Unnikrishnan (5) , Giorgio Levy (2) , Massimiliano Marangolo (6) , Mamhoud Eddrief (6) , Damjan Krizmancic (1) , Huiwen Ji (7) , Andrea Damascelli (2) , Gerrit van Der Laan , Russell G. Egdell (8) , Robert J. Cava (7)

1 IOM - CNR Istituto Officina dei Materiali
2 UBC - University of British Columbia
3 SSOLEIL - Synchrotron SOLEIL
4 LCPMR - Laboratoire de Chimie Physique - Matière et Rayonnement
5 INSP - Institut des Nanosciences de Paris
6 INSP - Institut des Nanosciences de Paris
7 Princeton University
8 University of Oxford

The influence of magnetic dopants on the electronic and chemical environments in topological insulators (TIs) is a key factor when considering possible spintronic applications based on topological surface state properties. Here we provide spectroscopic evidence for the presence of distinct chemical and electronic behavior for surface and bulk magnetic doping of Bi2Te3. The inclusion of Mn in the bulk of Bi2Te3 induces a genuine dilute ferromagnetic state, with reduction of the bulk band gap as the Mn content is increased. Deposition of Fe on the Bi2Te3 surface, on the other hand, favors the formation of iron telluride already at coverages as low as 0.07 monolayer, as a consequence of the reactivity of the Te-rich surface. Our results identify the factors that need to be controlled in the realization of magnetic nanosystems and interfaces based on TIs.

Domaines: Matière Condensée [cond-mat]

Ivana Vobornik, Giancarlo Panaccione, Jun Fujii, Zhi-Huai Zhu, Francesco Offi, et al.. Observation of Distinct Bulk and Surface Chemical Environments in a Topological Insulator under Magnetic Doping. Journal of Physical Chemistry C, 2014, 118 (23), pp.12333-12339. ⟨10.1021/jp502729u⟩. ⟨hal-01240502⟩