Dresden 2026 – scientific programme
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DS: Fachverband Dünne Schichten
DS 4: Thin Film Properties II
DS 4.1: Talk
Monday, March 9, 2026, 16:30–16:45, REC/C213
Epitaxial Growth and Structural Characterization of Non-centrosymmetric B20-PtAl Thin Films — •Ayusa Aparupa Biswal1, Darius Pohl2, Bernd Rellinghaus2, Edouard Lesne1, and Claudia Felser1 — 1Max-Planck-Institute für Chemische Physik fester Stoffe, Dresden, Germany — 2Dresden Center for Nanoanalysis (DCN), cfaed, TU Dresden, Dresden, Germany
Topological chiral semimetals with the non-centrosymmetric cubic B20 structure (space group P213) are distinguished by chirality in their crystal, magnetic, and electronic structures [1]. B20 compounds do not possess inversion or mirror symmetry but preserve rotational symmetries. Non-magnetic B20 compounds, such as CoSi, RhSi, PdGa, and PtAl, host multifold fermions originating from topological band crossings. These lead to large Chern numbers and produce Fermi arcs, alike those found in Weyl semimetals [2,3]. We report on the heteroepitaxial growth of crystalline PtAl thin-films with a non-centrosymmetric cubic B20 structure. We employ magnetron sputtering and explore the phase space of sample composition, growth temperature, post-annealing process, as well as resorting to suitable substrates and crystalline buffer layers. The samples are structurally characterized by a combination of X-ray diffraction and atomic-scale high-resolution transmission electron microscopy, which reveals a thickness-dependent microstructure of the B20 films, attributable to a combination of strain relaxation and the formation of extended defects, which are under detailed investigation. [1] B. Bradlyn et al., Science 353 (2016).[2] D. S. Sanchez, et al., Nature 567 (2019).[3] Z. Rao et al., Nature 567 (2019).
Keywords: B-20 compounds; High Resolution Transmission Electron Microscopy; Thin Film-magnetron Sputtering; Non-centrosymmetric; Chiral compound