The formation of SMACs (upper left), flowchart for screening TM elements capable of forming SMACs (bottom left), false-colored HAADF-STEM images of Ni SMACs in MoS2 (upper right), and magnified, simulated HAADF-STEM images and atomic models of Ni SMACs (bottom right). [Photo/en.nuaa.edu.cn]
A research team led by Academician Guo Wanlin, Professor Zhang Zhuhua, and Associate Researcher Qiao Ruixi of the Institute for Frontier Science at Nanjing University of Aeronautics and Astronautics, in collaboration with Professor Liu Zheng of Nanyang Technological University, has achieved a significant breakthrough in the fabrication of single-metal-atom chains.
The findings, published under the title Coherently Confined Single-Metal-Atom Chains in 2D Semiconductors, were recently released online in Nature Communications.
Research background
One-dimensional (1D) nanostructures represent the smallest dimension that maintains efficient electron transport, and thus have been deemed critical to the functionality and integration of nanoscale devices.
Single-metal-atom chains (SMACs), the ultimate manifestations of 1D structures, can confine electrons within an absolutely 1D space. This characteristic renders SMACs as a unique platform to investigate a series of intriguing quantum transport behaviors and correlation effects, including quantized conductance, opening up a wealth of opportunities for cutting-edge applications in electronics, magnetism, and optics.
There have been two typical synthesis approaches for fabricating SMACs. One is the top-down mechanical stretching method for suspended SMACs, while the other is the self-assembly method for supported SMACs. However, the atomic chains fabricated using these methods suffer from low yield and limited chain length. Moreover, most of the reported SMACs exhibit structural vulnerability and poor ambient stability.
The NUAA research team proposes a computational protocol to identify transition metals capable of forming SMACs along mirror twin boundaries in two-dimensional metal dichalcogenides. Taking MoS2 as a prototypical example, the team's thermodynamics and kinetics calculations indicate that Co, Ni, Rh, Pd, and Pt atoms can be enticed by the progressive formation of mirror twin boundaries to yield robust SMAC. These findings are supported by successful experimental synthesis of Co-, Ni-, Pd- and Pt-based SMACs using a chemical vapor co-deposition method. These results lay a solid foundation for investigating exotic transport behaviors within extremely confined channels.
Link to the full paper: https://doi.org/10.1038/s41467-025-60127-3
