Molecular dynamics study on the fracture behavior of SiGe nanowire with twist grain boundary under tension

C Qiao and JF Song and HW Zhang and ZH Zhu and ZY Zhang and YZ Chen and SZ Wang and YJ Niu and YL Cao and Z Fang, PHYSICA SCRIPTA, 100, 0759b6 (2025).

DOI: 10.1088/1402-4896/aded3e

Crystalline SiGe combining the excellent properties of silicon and germanium plays a key role inmodern electronics and optoelectronics technology. In contrast to the extensive researches onelectronic and photoelectric properties, here we turn the attention on the mechanical property. Byusing the molecular dynamics simulations, the fracture behaviors of the001,110and111orientated SiGe nanowire with and without twist grain boundary are investigated in the tensionprocess. The results reveal that the twist grain boundary play an important role in the mechanicalproperty of SiGe nanowire as it can inhibit the dislocation atoms from moving along the axialorientation. The fracture behavior of the SiGe nanowire with twist grain boundary is sensitive to thetwist angle, radius and temperature. Both the Young's modulus and maximum stress decrease as thetwist angle increases from 8 degrees to 19 degrees or the temperature increases from 50 K to 600 K, while they areenhanced as the radius of nanowire increases. As for the fracture strain, it changes slightly with theradius of nanowire, but decreases with the increasing twist angle and temperature. Interestingly that,the fracture behavior occurs at the twist grain boundary regardless of the twist angle, radius andtemperature. Our studies enrich the knowledge of mechanical characteristic of SiGe nanowire withtwist grain boundary, which paves the way for processing and device design

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