A hybrid density functional study on the mechanochemistry of silicon carbide nanotubes

Abstract

The constrained geometries simulate the external force (CoGEF) method mimics the application of external stress on molecules. Herein, we used the CoGEF method at the hybrid density functional theory level to investigate the behavior of silicon carbide nanotubes (SiCNTs) under longitudinal stress. When the SiCNTs are under longitudinal stress, we observe a gradual decrease in the binding energy and the frontier orbital gap with the applied strain until a critical threshold is reached. Beyond this threshold, a sudden increase in both parameters occurs, indicating the formation of some kind of stable structure. The higher binding energy of the larger SiCNTs makes them more resistant to rupture under strain, suggesting their increased mechanical strength. Additionally, we observed a rapid initial increase of Young's modulus of SiCNTs and convergence to a constant magnitude with further increase in their diameter. Therefore, CoGEF analysis provides invaluable insights into the changes occurring in the structural and electronic properties of SiCNTs when subjected to stress.