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.
@article{arxiv.1408.2971,
title = {Observation of Distinct Bulk and Surface Chemical Environments in a Topological Insulator under Magnetic doping},
author = {Ivana Vobornik and Giancarlo Panaccione and Jun Fujii and Zhi-Huai Zhu and Francesco Offi and Benjamin R. Salles and Francesco Borgatti and Piero Torelli and Jean Pascal Rueff and Denis Ceolin and Alberto Artioli and Manju Unnikrishnan and Giorgio Levy and Massimiliano Marangolo and Mamhoud Eddrief and Damjan Krizmancic and Huiwen Ji and Andrea Damascelli and Gerrit van der Laan and Russell G. Egdell and Robert J. Cava},
journal= {arXiv preprint arXiv:1408.2971},
year = {2014}
}