Abstract Transverse compression and chemical passivation of few graphene or hexagonal boron nitride layers have been shown to be viable means to form ultrathin membranes rich in sp 3 bonds exhibiting intriguing mechanical behaviors. Here, density functional theory calculations are used to calculate second- and third-order elastic constants, as well as ideal breaking strengths of both layered and sp 3 -bonded arbon and boron nitride films. The sp 3 -bonded membranes consist of two or three planes of both existing and new in silico-designed bulk structures of carbon and boron nitride, and have either both, one, or none of the surfaces passivated with hydrogen. This study shows that carbon and boron nitride membranes rich in sp 3 bonds exhibit mechanical properties and ideal breaking strengths that compete with those of sp 2 -bonded layered films, and that there is a plethora of plausible stable structures of such sp 3 -bonded membranes, showing diverse electronic properties, and longitudinal and transverse mechanical behaviors. This study also suggests that by controlling thickness of the film and by tuning chemistry of the supporting substrate, transverse compression of layered carbon or hexagonal boron nitride films could lead to the formation of stable sp 3 -bonded 2D materials exposing clean surfaces, and therefore transferable, and exhibiting intriguing anisotropic mechanical and electronic properties.

中文翻译：

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sp3 键合碳和氮化硼二维膜的机械性能：第一性原理研究

摘要 少量石墨烯或六方氮化硼层的横向压缩和化学钝化已被证明是形成富含 sp 3 键的超薄膜的可行手段，该薄膜表现出有趣的机械行为。在这里，密度泛函理论计算用于计算二阶和三阶弹性常数，以及层状和 sp 3 键合的碳和氮化硼薄膜的理想断裂强度。sp 3 键合膜由碳和氮化硼硅设计的块状结构中现有的和新的两个或三个平面组成，并且具有两个、一个或没有被氢钝化的表面。这项研究表明，富含 sp 3 键的碳和氮化硼膜表现出的机械性能和理想的断裂强度可与 sp 2 键合的层状膜相媲美，并且这种 sp 3 键合膜存在大量合理的稳定结构，显示出不同的电子特性以及纵向和横向机械行为。该研究还表明，通过控制薄膜的厚度和调节支撑衬底的化学性质，层状碳或六方氮化硼薄膜的横向压缩可导致形成稳定的 sp 3 键合 2D 材料，暴露干净的表面，因此可转移，并表现出有趣的各向异性机械和电子特性。