Influence of Composition and Temperature on Mechanical Response and Strain Energy Distribution of Silicon-Germanium

In this study, mechanical response and train energy distribution of silicon-germanium are investigated via a tensile test using molecular dynamics (MD) simulation. The results demonstrate that the ultimate tensile stress (UTS) decreases moderately as the Si composition increases from 20% to 40%, but then drops sharply as the Si composition continues to rise to 80%. The UTS value increases as the sample thickness rises from 1 to 2 nm; however, it decreases moderately as the thickness further increases from 2 to 5 nm. The Si50Ge50 alloy exhibits the highest durability compared to the other samples, while the Si40Ge60 alloy shows a weakness in durability, as it fractures when strain reaches 0.2. The Si50Ge50 alloy demonstrates significant durability at 750 K for sample thicknesses of 1, 2, and 3 nm. The strain energy is evenly distributed across the entire specimen, allowing it to absorb more external energy.