Molecular Dynamics Simulation of the Uniaxial Tensile Test of Hollow-Core Silicon Nanowires

Abstract

In this paper, the mechanical behavior of silicon nanowires with the hollow-core geometry was investigated using molecular dynamics simulation. The pristine Si nanowires are considered as references to compare the mechanical properties of the hollow-core structures. Our results show that hollow-core silicon nanowires with a cavity volume fraction above 50% have a larger fracture strain compared to nanowires with a smaller cavity. Under uniaxial tensile loading, the computed Young’s modulus decreases as the radius of cylindrical cavity in nanowire increases. To understand the mechanical behavior of hollow-core Si nanowires, the structural evolution of the nanowire with different cavity volume fraction was investigated. It is established that the structure of nanowires with a cavity volume of more than 50% is completely amorphous. We have shown that structural changes in nanowires are the root cause of changes in their mechanical behavior.