Molecular dynamics study of mechanical properties of bismuth telluride nanofilm

A molecular dynamics (MD) simulation has been carried out to evaluate the mechanical properties of Bi2Te3 nanofilm, and all the simulation results are compared with that of Bi2Te3 bulk. After the stable free-relaxation state has been obtained, the radial distribution function of Bi2Te3 nanofilm is computed to validate its crystal structure. The distributions of potential energy and stress along the thickness direction are obtained. It is found that the surface atoms possess high potential energy; the surface of the nanofilm undergoes tensile stress, while the inside undergoes compressive stress. Tension simulations have been conducted to evaluate the mechanical properties (including Young’s modulus, ultimate strength and failure strain) of the nanofilm. The effects of surface, size, and temperature on the calculating results of Bi2Te3 nanofilm are discussed in detail.