Thermal stability and mechanical properties of Si/Ge superlattice nanowires having inclination interfaces from simulations at atomic scale

Molecular dynamics simulations were performed to investigate the packing changes and mechanical properties of the Si/Ge superlattice nanowires with tilted interfaces. Using potential energy, Lode-Nadai parameters, and atomic pressure as well as visually packing images, the thermal stability and bearing-load capacity are identified at elevated temperatures. The stress–strain curves for these nanowires having different interfaces along typical crystal growth directions suggest that there are different stages including elastic deformation, yield, necking, and fracture during tension at room temperature. The simulation results reveal that the size and the layer thickness have great influence on thermal stability and mechanical properties of these nanowires. Their elasticity and tensile strength of the nanowires as well as the plastic deformation are significantly affected by the layer’s thickness and bonding in the interfaces. The atomic pressure and Lode-Nadai parameters of these nanowires at room temperature provides the details of stress and bearing load at atomic scale.