Size-dependent brittle-to-ductile transition in GaAs nano-rods. (December 2015)

• Record Type: Journal Article
• Authors: Wang, J.; Shen, Y.G.; Song, F.; Ke, F.J.; Bai, Y.L.; Lu, C.
• Is Part Of: Engineering fracture mechanics. Volume 150(2015)
• Page Start: 135
• Page End: 142
• Publication Date: 2015-12
• Subjects: Molecular dynamics simulation -- GaAs nano-rods -- Brittle-to-ductile transition -- Dislocation -- Size effect; Fracture mechanics -- Periodicals; Rupture, Mécanique de la -- Périodiques; Fracture mechanics; Periodicals; 620.112605
• DOI: 10.1016/j.engfracmech.2015.04.006
• Languages: English
• ISSNs: 0013-7944

Abstract

Highlights: The uniaxial compressive behavior of GaAs nano-rods was investigated by using molecular dynamics. Buckling beyond the elastic limit induces a competition between generation of cracks and initiation of dislocations. Dislocation activities dominate plastic deformation and whilst the preference to cracks yields brittle fracture. The brittle-to-ductile transition is significantly size-dependent. Abstract: GaAs is brittle at room temperature at the macro-scale; however, ductility emerges when its characteristic dimension reduces to the nano-scale. Using molecular dynamics simulations, we reveal that there is a brittle-to-ductile transition in GaAs nano-rods due to the competition between generation of cracks and initiation of dislocations. Such a competition is sensitive to aspect ratios of nano-rods. These results well explain experimentally observed ductility of GaAs nano-rods and have important implications for the design of semiconductor materials with tailored mechanical properties.