npj 2D Materials and Applications (Sep 2024)

Metastable square Bismuth allotrope oriented by six-fold symmetric mica

  • Nan Wu,
  • Xiangchen Hu,
  • Yinliang Tang,
  • Congcong Wu,
  • Yu Chen,
  • Yiyuan Ren,
  • Zhuo Zhang,
  • Yi Yu,
  • Hung-Ta Wang

DOI
https://doi.org/10.1038/s41699-024-00495-4
Journal volume & issue
Vol. 8, no. 1
pp. 1 – 9

Abstract

Read online

Abstract Layered bismuth (Bi) has been focused on two Peierls distortion derivatives, i.e., bulk stable β-phase (A7 phase), black phosphorus-like α-phase (A17 phase), and their mutated structures. Metastable structures beyond Peierls distortion system are yet rarely accessible. Here, Bi in square symmetry ( $${C}_{4v}$$ C 4 v ), called s-Bi, was grown via physical vapor deposition. The co-existence of three 120°-associated s-Bi crystal grains was analyzed using transmission electron microscopy. 120°-oriented one-dimensional (1D) nuclei indicate s-Bi heteroepitaxy on six-fold symmetric ( $${C}_{6v}$$ C 6 v ) mica (001). A subsequent nanorod-like nuclei coalescing could promote a morphology evolution, resulting in triangular or hexagonal nanosheets with the unique triple s-Bi structure suitable for later β-Bi growth. Lattice misfit and strain calculations suggest a supercell match between $$4\times 7$$ 4 × 7 s-Bi and $$3\times 3$$ 3 × 3 mica (001). This work demonstrates the metastable s-Bi structure via anisotropic heteroepitaxy of $${C}_{4v}$$ C 4 v s-Bi on $${C}_{6v}$$ C 6 v mica.