Beyond Graphene: Scientists Create Ultra-Thin 2D Metals for the First Time
Dr. Aseel S. Hamzah
A new method called Van der Waals (vdW) squeezing enables the creation of stable, atomically thin 2D metals, opening doors to advanced devices and fundamental discoveries in materials science. Researchers from the Institute of Physics (IOP) of the Chinese Academy of Sciences have developed a convenient, universal, atomic-level manufacturing technique—called vdW squeezing—for the production of 2D metals at the angstrom thickness limit. This study was recently published in Nature. The manufacturing technique involves melting and squeezing pure metals between two rigid vdW anvils under high pressure. With this method, the researchers produced diverse atomically thin 2D metals, including Bi (~6.3 Å), Sn (~5.8 Å), Pb (~7.5 Å), In (~8.4 Å) and Ga (~9.2 Å). The vdW anvils consist of two single-crystalline MoS2 monolayers epitaxially grown on sapphire. The anvils are essential for producing 2D metals for two reasons. First, the atomically flat, dangling-bond-free surface of the monolayer MoS2/sapphire ensures uniform 2D metal thickness over a large scale. Second, the high Young’s modulus of both sapphire and monolayer MoS2 (> 300 GPa) allows them to withstand extreme pressures, enabling 2D metals formed between the two anvils to approach their angstrom thickness limit.
Al-Mustaqbal University, the First in Iraq.