SKM 2023 – scientific programme
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O: Fachverband Oberflächenphysik
O 30: 2D Materials I: Electronic Structure
O 30.4: Talk
Tuesday, March 28, 2023, 11:15–11:30, GER 37
Investigation of phase-transitions in MoTe2 using ToF-MM — •O. Fedchenko1, F. Diekmann2, K. Medjanik1, M. Kallmayer3, S. Babenkov1, D. Vasilyev1, O. Tkach1, M. Souliou4, M. Frachet4, M. Le Tacon4, K. Roßnagel2, A. Winkelmann5, G. Schönhense1, and H.-J. Elmers1 — 1JGU, Institut für Physik, Mainz, Germany — 2Institut für Experimentelle und Angewandte Physik, CAU Kiel, Germany — 3Surface Concept GmbH, Mainz — 4KIT, IQMT, Karlsruhe, Germany — 5ACMN, AGH University of Science and Technology, Krakow, Poland
MoTe2 is unique among transition metal dichalcogenides (TMDCs) because it can be grown in both the semiconducting (2H) and semimetallic (1T’) phase. The transitions between these phases can be controlled with temperature and doping concentration. Using time-of-flight momentum microscopy (ToF-MM), the thermally-induced inversion symmetry breaking in doped Mo1−xWxTe2 is investigated. Pristine MoTe2 and Mo0.98W0.02Te2 take the 2H phase, which does not show any thermal induced phase transition. For increased W doping concentration we obtain the metastable monoclinic 1T’ phase at 300K (RT), which then can be transformed to the orthorhombic Td phase at T<170 K (LT). Raman and XRD measurements confirm the structural transitions.The Td-phase exhibits topological states identified by Fermi arcs, up to binding energy of EB = 75 meV.