ICT2014 Abstracts

Along the c axis of crystal lattice, Bi₂Te₃ has periodic quintuple layers “- Te1 - Bi - Te2 - Bi - Te1 -” which are connected by Van der Waals bonding. The weak bonding between Te1-Te1 layers should significantly affect the mechanical properties of Bi₂Te₃, especially for the compression properties. In this paper, the molecular dynamics method has been employed to study the mechanical properties of cuboid single-crystal bulk Bi₂Te₃ under compressive loads. The emphasis are put on the effects of the Van der Waals bonding on the deformation and failure mechanism. The molecular dynamics simulation results show that the Van der Waals bonding plays a dominant role in the mechanism of deformation, and fundamentally determines the ultimate stress and fracture strain. Furthermore, compressive load along and perpendicular to the c axis can lead to quite different failure modes, which can be distinguished by their specific effects on the deformation of the Van der Waals bonding. However, only models with the load perpendicular to the c axis dramatically demonstrate the strain rate effect on the stress–strain curves, just according to its poor structural stability.

Key words: Bi₂Te₃, Van der Waals bonding, compression properties, molecular dynamics.