Atomistic simulation of brittle to ductile transition in GaN nanotubes

Molecular dynamics methods with a Stillinger-Weber [Phys. Rev. B 31, 5262 (1985)] potential have been used to investigate the mechanical properties of wurtzite-type single-crystalline GaN nanotubes under applied tensile strains. At low temperatures, the nanotubes show brittle properties, whereas at high temperatures, they behave as ductile materials. The brittle to ductile transition (BDT) is systematically investigated and the corresponding transition temperatures have been determined in GaN nanotubes. The BDT temperature generally increases with increasing thickness of nanotubes and strain rate. (c) 2006 American Institute of Physics.