Mechanical properties of diamane: Orientation dependence of strength and fracture strain

Abstract

Diamane, the two-dimensional counterpart of diamond, is very promising for novel electronic and nanomechanical devices, which requires additional studies on their physical and mechanical properties. In the present work, the orientation dependence of diamane strength with the detailed analysis of the deformation behavior was carried out by molecular dynamics. Two stacks of diamane layers covered with hydrogen with different chirality θ from 0 to 30° were considered. The atomic stacking of diamane has no effect on its strength. It was found that diamane strength depends non-monotonously on the diamane chirality: the highest strength was found for θ = 10°. The fracture strain decreases with the increase of chiral angle from 0 to 20° and does not change for chirality from 20 to 30°. However, the Young’s modulus does not depend on the diamane chirality. The main deformation mechanisms were revealed: elongation of covalent bonds and rotation of valence angles. For chiral angles from 0 to 20°, the diamane chirality can be controllably changed during tension which results in the increase in fracture strength and strain. The obtained results allow a better understanding of the effect of the diamane morphology on their mechanical properties for future applications.