Interfacial reactions at Fe/topological insulator spin contacts

This is the authors' abstract. We don't add key points for this paper.

The authors study the composition and abruptness of the interfacial layers that form during deposition and patterning of a ferromagnet, Fe on a topological insulator (TI), Bi2Se3, Bi2Te3, and SiOx/Bi2Te3. Such structures are potentially useful for spintronics. Cross-sectional transmission electron microscopy, including interfacial elemental mapping, confirms that Fe reacts with Bi2Se3 near room temperature, forming an abrupt 5 nm thick FeSe0.92 single crystalline binary phase, predominantly (001) oriented, with lattice fringe spacing of 0.55 nm. In contrast, Fe/Bi2Te3 forms a polycrystalline Fe/TI interfacial alloy that can be prevented by the addition of an evaporated SiOx separating Fe from the TI.