Abidi Kameyab Raza, Koskinen Pekka
Nanoscience Center, Department of Physics, University of Jyväskylä, 40014 Jyväskylä, Finland.
Nanoscale. 2024 Oct 31;16(42):19649-19655. doi: 10.1039/d4nr03266g.
Metallenes are atomically thin two-dimensional (2D) materials lacking a layered structure in the bulk form. They can be stabilized by nanoscale constrictions like pores in 2D covalent templates, but the isotropic metallic bonding makes stabilization difficult. A few metallenes have been stabilized but comparison with theory predictions has not always been clear. Here, we use density-functional theory calculations to explore the energetics and dynamic stabilities of 45 metallenes at six lattices (honeycomb, square, hexagonal, and their buckled counterparts) and varying atomic densities. We found that of the 270 different crystalline lattices, 128 were dynamically stable at sporadic densities, mostly under tensile strain. At the energy minima, lattices were often dynamically unstable against amorphization and the breaking down of metallene planarity. Consequently, the results imply that crystalline metallenes should be seen through a novel paradigm: they should be considered not as membranes with fixed structures and lattice constants but as yielding membranes that can be stabilized better under tensile strain and low atomic density. Following this paradigm, we rank the most promising metallenes for 2D stability and hope that the paradigm will help develop new strategies to synthesize larger and more stable metallene samples for plasmonic, optical, and catalytic applications.
金属烯是原子级薄的二维（2D）材料，其块状形式缺乏层状结构。它们可以通过纳米级收缩（如二维共价模板中的孔）来稳定，但各向同性的金属键使得稳定化变得困难。已经有一些金属烯被稳定下来，但与理论预测的比较并不总是清晰的。在这里，我们使用密度泛函理论计算来探索45种金属烯在六种晶格（蜂窝晶格、方形晶格、六边形晶格及其屈曲对应晶格）和不同原子密度下的能量学和动态稳定性。我们发现，在270种不同的晶体晶格中，有128种在零星密度下是动态稳定的，大多处于拉伸应变下。在能量最小值处，晶格通常对非晶化和金属烯平面性的破坏是动态不稳定的。因此，结果表明，晶体金属烯应通过一种新的范式来看待：它们不应被视为具有固定结构和晶格常数的膜，而应被视为在拉伸应变和低原子密度下能更好地稳定的可屈服膜。遵循这一范式，我们对二维稳定性最有前景的金属烯进行了排名，并希望该范式将有助于开发新策略，以合成用于等离子体、光学和催化应用的更大、更稳定的金属烯样品。
