Effect of surface energy on size-dependent deformation twinning of defect-free Au nanowires.
In this study, we report the size-dependent transition of deformation twinning studied using in situ SEM/TEM tensile testing of defect-free [110] Au nanowires/ribbons with controlled geometry. The critical dimension below which the ordinary plasticity transits to deformation twinning is experimentally determined to be ∼170 nm for Au nanowires with equilateral cross-sections. Nanoribbons with a fixed thickness but increased width-to-thickness ratios (9 : 1) were also studied to show that an increase in the surface energy due to the crystal re-orientation suppresses the deformation twinning. Molecular dynamics simulations confirmed that the transition from partial dislocation mediated plasticity to perfect dislocation plasticity with increase in the width-to-thickness ratio is due to the effect of the surface energy.
Graduate School of Energy Environment Water and Sustainability, Korea Advanced Institute of Science & Technology, Daejeon, Republic of Korea 305-701. smhan01@kaist.ac.kr bongsoo@kaist.ac.kr.
Byungil
B
Hwang
Mijeong
M
Kang
Subin
S
Lee
Christopher R
CR
Weinberger
Phillip
P
Loya
Jun
J
Lou
Sang Ho
SH
Oh
Bongsoo
B
Kim
Seung Min
SM
Han