A research team led by Roman Nowak, who serves at Aalto University’s Nordic Hysitron Laboratory, has discovered that materials such as silicon are brittle in larger sizes but when the material is of a nano-size, it can be squeezed into 50% of its size without causing breakage.
The researchers tracked the rearrangements at atomic level due to squeezing of small silicon spheres. They observed that the material’s responsiveness differs with the scale of deconfinement. This finding contradicts the renowned ‘size effect’ phenomenon. The compression of material results in unpredicted deformation mechanisms under mechanically stimulated shape changes.
In its bulk form, materials like silicon demonstrate plasticity due to phase transformations. Nevertheless, the scientists discovered that advancement from a relatively bulk constrained state to a less constrained nanoparticle state changes the mechanical response of silicon.
The discovery of the ‘nanoscale confinement’ factor has never openly been considered until now for size dependent phenomena. It solves issues encountered by previous studies and expands options for nanoscale device design. It will favor the large-scale development of next-generation nanostructures.
The research lays the foundation for studying the incipient plasticity characteristics in nanovolumes, hence being instrumental in producing crystal defects that drastically affect biocompatibility and functional properties. This finding could affect design of next-generation nano-devices, including biological markers, drug delivery, lasers on a chip and ultraviolet photo detectors.
Source: http://www.aalto.fi