Effects of Structure, Temperature, and Strain Rate on Mechanical Properties of SiGe Nanotubes

X Liu and DP Cao and AP Yu, JOURNAL OF PHYSICAL CHEMISTRY C, 114, 4309-4316 (2010).

DOI: 10.1021/jp910423k

The effects of structure, temperature, and strain rate oil mechanical properties of all the SiGe nanotubes in armchair and zigzag Structures (n = 4-13) in two atomic arrangement types are investigated by classical molecular dynamics simulation. During the extending tests, we observe three Structural transformations from initial structure, tensile Structure, to critical Structure deformation. The simulation results indicate that the Young's Modulus of nanotubes is closely dependent on their diameter, chirality, and arrangement structure. The type I (alternating atom arrangement type) armchair SiGe nanotube exhibits the largest Young's modulus, compared with other nanotubes with the same index n. By exploring the effects of temperature and strain rate oil mechanical properties of SiGe nanotubes, it is found that the higher temperature and lower strain rate lead to the lower critical strain and tensile strength. Furthermore, it is also found that the critical strains for both armchair and zigzag nanotubes in two arrangement types are significantly dependent oil the tube diameter and chirality. The armchair type I nanotube exhibits the highest mechanical critical strain and tensile strength among all these nanotubes with the same index n. Oil the basis of the transition-state theory model, we predict that the critical strain of the SiGe (6,6) type I nanotube at 300 K, stretched with a strain rate of 5%/h, is about 3.38%, which is in good agreement with the recent experimental results. Our results Might provide potential applications in Manipulating mechanical and electromechanical properties Of the nanostructures suitable for electronic devices.

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