nl9b04164_si_001.pdf (1.11 MB)
Tunable Anelasticity in Amorphous Si Nanowires
journal contribution
posted on 2019-12-12, 20:16 authored by Yuecun Wang, Beiming Liang, Shuigang Xu, Lin Tian, Andrew M. Minor, Zhiwei ShanIn situ bending tests of amorphous Si nanowires (a-Si
NWs) found
different elastic behavior depending on whether they were straight
or curved to begin with. The axially straight NWs exhibit pure elastic
deformation; however, the axially curved NWs exhibit obvious anelastic
behavior when they are bent in the direction of original curvature.
On the basis of STEM-EELS analysis, we propose that the underlying
mechanism for this anelastic behavior is a bond-switching assisted
redistribution of the nonuniform density (structure) in the curved
NWs under the inhomogeneous stress field. This mechanism was further
supported by the fact that the originally straight a-Si NWs also display
similar anelasticity with the as-grown curved NWs after focused ion
beam irradiation that can cause nonuniform structure distribution.
As compared to what has been reported in other 1D materials, the anelasticity
of a-Si NWs can be tuned by modifying their morphology, controlling
the loading direction, or irradiating them via ion beam. Our findings
suggest that a-Si NWs could be a promising material in the nanoscale
damping systems, especially the semiconductor nanodevices.