Berlin 2015 – scientific programme

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DS: Fachverband Dünne Schichten

DS 26: Layer Properties: Electrical, Optical, and Mechanical Properties

DS 26.6: Talk

Wednesday, March 18, 2015, 16:15–16:30, H 2032

Weak antilocalization and disorder induced electron-electron-interaction in DC-magnetron-sputtered Sb₂Te₃ and Bi₂Te₃ thin films — •Tobias Schäfer¹, Hanno Volker¹, and Matthias Wuttig^1,2 — ¹I. Physikalisches Institut (IA), RWTH Aachen University, 52056 Aachen, Germany — ²JARA FIT, RWTH Aachen

Recently Sb₂Te₃ and Bi₂Te₃ have raised notable interest as topological insulators (TIs). A usual deposition technique for TI specimen is molecular beam epitaxy (MBE) as it ensures the required high crystalline and surface quality. Besides ARPES, low temperature magneto-transport measurements have become common techniques for characterization of Sb₂Te₃ and Bi₂Te₃ TI samples^[1].

Apart from that, the materials are also interesting as phase change materials (PCM). Particularly Sb₂Te₃ is known for its fast and reversible switching between an amorphous and a crystalline phase^[2]. In this context DC-magnetron sputtering followed by subsequent annealing is the commonly used deposition technique, which leads to more disordered films that do not suit the needs of TI surface states.

Here we present a magneto-transport study on highly disordered Sb₂Te₃ and Bi₂Te₃ thin films. The thicknesses are chosen to be smaller than the inelastic mean free path in order to achieve a quasi 2d behavior. The measurements are analyzed in the framework of HLN-theory^[3] and compared to literature on MBE grown TI samples.

^[1] e.g. Takagaki et al, Phys. Rev. B 86, 125137, (2012)

^[2] Yamada et al, Jpn. J. Appl. Phys. 26 61, (1987)

^[3] Hikami et al, Prog. Theor. Phys. 63 (2), (1980)