The key role of nanoscale surface facets on the mechanical strength and failure of wurtzite and periodically twinned zinc-blende nanowires
R Grantab and VB Shenoy, PHILOSOPHICAL MAGAZINE LETTERS, 91, 280-286 (2011).
Using molecular dynamics, we study the role of the surface facets of III-V nanowires on their failure during tensile deformation. We find that wurtzite (WZ) nanowires can withstand higher levels of stress and strain at failure compared to zinc-blende (ZB) nanowires. We observe that it is easier to nucleate a crack on a ZB nanowire due to the stress singularities that occur at the intersection of two opposing 111 facets. In WZ nanowires, we observe that cracks always nucleate at the intersection between two adjacent 11 (2) over bar surface facets. We explain these phenomena using fracture mechanics techniques based on energetics of crack formation.
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