TY - JOUR

T1 - A first-principles study on the physical properties of two-dimensional Nb3Cl8, Nb3Br8 and Nb3I8

AU - Mortazavi, Bohayra

AU - Zhuang, Xiaoying

AU - Rabczuk, Timon

N1 - Funding Information: B.M. and X.Z. appreciate the funding by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy within the Cluster of Excellence PhoenixD (EXC 2122, Project ID 390833453). B. M and T. R. are greatly thankful to the VEGAS cluster at Bauhaus University of Weimar for providing the computational resources.

PY - 2022/9/29

Y1 - 2022/9/29

N2 - In a recent advance, Nb3Cl8 two-dimensional crystals with a kagome lattice and electronic topological flat bands have been experimentally fabricated (Sun et al. in Nano Lett 22:4596–4602, 2022). In this work motivated by the aforementioned progress, we conduct first-principles calculations to explore the structural, phonon dispersion relations, single-layer exfoliation energies and mechanical features of the Nb3X8 (X = Cl, Br, I) nanosheets. Acquired phonon dispersion relations reveal the dynamical stability of the Nb3X8 (X = Cl, Br, I) monolayers. To isolate single-layer crystals from bulk counterparts, we predicted exfoliation energies of 0.24, 0.27 and 0.28 J/m2, for the Nb3Cl8, Nb3Br8 and Nb3I8 monolayers, respectively, which are noticeably lower than that of the graphene. We found that the Nb3X8 monolayers are relatively strong nanosheets with isotropic elasticity and anisotropic tensile strength. It is moreover shown that by increasing the atomic weight of halogen atoms in the Nb3X8 nanosheets, mechanical characteristics decline. Presented results provide a useful vision about the key physical properties of novel 2D systems of Nb3X8 (X = Cl, Br, I).

AB - In a recent advance, Nb3Cl8 two-dimensional crystals with a kagome lattice and electronic topological flat bands have been experimentally fabricated (Sun et al. in Nano Lett 22:4596–4602, 2022). In this work motivated by the aforementioned progress, we conduct first-principles calculations to explore the structural, phonon dispersion relations, single-layer exfoliation energies and mechanical features of the Nb3X8 (X = Cl, Br, I) nanosheets. Acquired phonon dispersion relations reveal the dynamical stability of the Nb3X8 (X = Cl, Br, I) monolayers. To isolate single-layer crystals from bulk counterparts, we predicted exfoliation energies of 0.24, 0.27 and 0.28 J/m2, for the Nb3Cl8, Nb3Br8 and Nb3I8 monolayers, respectively, which are noticeably lower than that of the graphene. We found that the Nb3X8 monolayers are relatively strong nanosheets with isotropic elasticity and anisotropic tensile strength. It is moreover shown that by increasing the atomic weight of halogen atoms in the Nb3X8 nanosheets, mechanical characteristics decline. Presented results provide a useful vision about the key physical properties of novel 2D systems of Nb3X8 (X = Cl, Br, I).

KW - Exfoliation energy

KW - Mechanical

KW - NbCl

KW - Phonon dispersion

UR - http://www.scopus.com/inward/record.url?scp=85139058973&partnerID=8YFLogxK

U2 - 10.1007/s00339-022-06011-z

DO - 10.1007/s00339-022-06011-z

M3 - Article

AN - SCOPUS:85139058973

VL - 128

JO - Applied Physics A: Materials Science and Processing

JF - Applied Physics A: Materials Science and Processing

SN - 0947-8396

IS - 10

M1 - 934

ER -