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arXiv · 2308.14159

Supercell formation in epitaxial rare-earth ditelluride thin films

Adrian Llanos·Salva Salmani-Rezaie·Jinwoong Kim·Nicholas Kioussis·David A. Muller·Joseph Falson
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Abstract

Square net tellurides host an array of electronic ground states and commonly exhibit charge-density-wave ordering. Here we report the epitaxy of DyTe$_{2-\delta}$ on atomically flat MgO (001) using molecular beam epitaxy. The films are single phase and highly oriented as evidenced by transmission electron microscopy and X-ray diffraction measurements. Epitaxial strain is evident in films and is relieved as the thickness increases up to a value of approximately 20 unit cells. Diffraction features associated with a supercell in the films are resolved which is coupled with Te-deficiency. First principles calculations attribute the formation of this defect lattice to nesting conditions in the Fermi surface, which produce a periodic occupancy of the conducting Te square-net, and opens a band gap at the chemical potential. This work establishes the groundwork for exploring the role of strain in tuning electronic and structural phases of epitaxial square-net tellurides and related compounds.

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Adrian Llanos, Salva Salmani-Rezaie, Jinwoong Kim, Nicholas Kioussis, David A. Muller, Joseph Falson. 2023-08-27. Supercell formation in epitaxial rare-earth ditelluride thin films. https://doi.org/10.1021/acs.cgd.3c00755

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