SKM 2023 – scientific programme

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DS: Fachverband Dünne Schichten

DS 12: Poster

DS 12.1: Poster

Wednesday, March 29, 2023, 17:00–19:00, P3

Growth and structural investigation of the SnBiTe stoichiometric series via MBE and TEM — •Xiao Hou¹, Abdur Rehman Jalil², Detlev Grützmacher², Claus Claus Michael Schneider¹, and Lukasz Plucinski¹ — ¹PGI-6, Forschungszentrum Jülich, Germany — ²PGI-9, Forschungszentrum Jülich, Germany

A topological phase transition (TPT) can be induced to engineer the band structure. This TPT is a fascinating, yet complex phenomenon in condensed matter research. Upon changing the stacking order of layers having different spin-orbit coupling (SOC) strengths, one can achieve a topological phase transition between trivial and nontrivial states [1,2]. Here, the Sn_xBi_yTe_z (SBT) stoichiometric series is a classical example, in which a stacking-dependent topological phase transformation group is explored.

The epitaxial growth of three distinct compositions i.e. SnBi₂Te₄, SnBi₄Te₇, Sn₂Bi₂Te₅ is conducted on Si (111) substrates via molecular beam epitaxy (MBE). X-ray diffraction (XRD) is employed to characterize the crystal quality of the grown thin films. We have also used advanced transmission electron microscopy (TEM) to investigate the stacking order. High-angle annular dark-field imaging provided detailed information about the crystallinity and atomic arrangements of the layer stacks and also of various types of structural defects in the thin films. The link between the stacking order and the topological characteristics requires further investigation that is ongoing.

[1] B.-J. Yang and N. Nagaosa, Nature Comm. 5, 4898 (2014). [2] R. Peng et al. Phys. Rev. B 101,115427 (2020).