Plastic deformation of indium nanostructures

Mechanical properties and morphology of cylindrical indium nanopillars, fabricated by electron beam lithography and electroplating, are characterized in uniaxial compression. Time-dependent deformation and influence of size on nanoscale indium mechanical properties were investigated. The results show two fundamentally different deformation mechanisms which govern plasticity in these indium nanostructures. We observed that the majority of indium nanopillars deform at engineering stresses near the bulk values (Type I), with a small fraction sustaining flow stresses approaching the theoretical limit for indium (Type II). The results also show the strain rate sensitivity and flow stresses in Type I indium nanopillars are similar to bulk indium with no apparent size effects.

► Indium nanopillars display two different deformation mechanisms.
► ∼80% exhibited low flow stresses near that of bulk indium.
► Low strength nanopillars have strain rate sensitivity similar to bulk indium.
► ∼20% of compressed indium nanopillars deformed at nearly theoretical strengths.
► Low-strength samples do not exhibit strength size effects.