| 1. |
- Sadowski, Janusz, et al.
(författare)
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Structural Properties of TaAs Weyl Semimetal Thin Films Grown by Molecular Beam Epitaxy on GaAs(001) Substrates
- 2022
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 22:10, s. 6039-6045
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Tidskriftsartikel (refereegranskat)abstract
- Thin crystalline layers of TaAs Weyl semimetal are grown by molecular beam epitaxy on GaAs(001) substrates. The (001) planes of the tetragonal TaAs lattice are parallel to the GaAs(001) substrate, but the corresponding in-plane crystallographic directions of the substrate and the layer are rotated by 45 degrees. In spite of a substantial lattice mismatch (about 19%) between the GaAs(001) substrate and TaAs epilayer, no misfit dislocations are observed at the GaAs(001)/TaAs(001) interface. Only stacking fault defects in TaAs are detected by transmission electron microscopy. Thorough X-ray diffraction measurements and analysis of the in situ reflection high-energy electron diffraction images indicate that TaAs layers are fully relaxed already at the initial deposition stage. Atomic force microscopy imaging reveals the columnar structure of the layers, with lateral (parallel to the layer's surface) columns about 20 nm wide and 200 nm long. Both X-ray diffraction and transmission electron microscopy measurements indicate that the columns share the same orientation and crystalline structure.
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| 2. |
- Seredynski, Bartlomiej, et al.
(författare)
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Molecular Beam Epitaxy of a 2D Material Nearly Lattice Matched to a 3D Substrate : NiTe2 on GaAs
- 2021
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Ingår i: Crystal Growth & Design. - : American Chemical Society (ACS). - 1528-7483 .- 1528-7505. ; 21:10, s. 5773-5779
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Tidskriftsartikel (refereegranskat)abstract
- The lattice mismatch between interesting 2D materials and commonly available 3D substrates is one of the obstacles in the epitaxial growth of monolithic 2D/3D heterostructures, but a number of 2D materials have not yet been considered for epitaxy. Here, we present the first molecular beam epitaxy growth of a NiTe2 2D transition-metal dichalcogenide. Importantly, the growth is realized on a nearly lattice-matched GaAs(111)B substrate. Structural properties of the grown layers are investigated by electron diffraction, X-ray diffraction, and scanning tunneling microscopy. Surface coverage and atomic-scale order are evidenced by images obtained with atomic force, scanning electron, and transmission electron microscopy. Basic transport properties were measured confirming that the NiTe2 layers are metallic, with a Hall concentration of 10(20) to 10(23) cm(-3), depending on the growth conditions.
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