Metal [100] Nanowires with Negative Poisson’s Ratio

Abstract

When materials are under stretching, occurrence of lateral contraction of materials is commonly observed. This is because Poisson’s ratio, the quantity describes the relationship between a lateral strain and applied strain, is positive for nearly all materials. There are some reported structures and materials having negative Poisson’s ratio. However, most of them are at macroscale, and reentrant structures and rigid rotating units are the main mechanisms for their negative Poisson’s ratio behavior. Here, with numerical and theoretical evidence, we show that metal [100] nanowires with asymmetric cross-sections such as rectangle or ellipse can exhibit negative Poisson’s ratio behavior. Furthermore, the negative Poisson’s ratio behavior can be further improved by introducing a hole inside the asymmetric nanowires. We show that the surface effect inducing the asymmetric stresses inside the nanowires is a main origin of the superior property.

On the Structural and Mechanical Properties of Poly(Phenylacetylene) Truss‐Like Hexagonal Hierarchical Nanonetworks

“…This means that the systems might lend themselves to some potential niche applications which require sudden changes in transverse dimensions upon reaching some critical load, such as smart sensors. Auxeticity which occurs after reaching some extent of applied strain has also been demonstrated before in other materials and structures at nanoscale as well as macroscale which also exhibit negative Poisson's ratio at finite strain …”

“…Auxeticity which occurs after reaching some extent of applied strain has also been demonstrated before in other materials and structures at nanoscale as well as macroscale which also exhibit negative Poisson's ratio at finite strain. [79][80][81][82][83][84][85] All this is very significant since it has been shown that these hierarchical nanoscale honeycombs, where the lower level is provided through a truss system exhibits some very useful properties, which when combined with other properties characteristic of polyphenylactylenes (e.g., the high conductivity due to the extensive electronic delocalisation of these systems) make them ideal for potential use in a number of applications which would require such systems. These could range from nanofilters (these systems benefit from the presence of zeolitelike pores which have dimensions in the nm scale) to components in electronic devices.…”

Non-destructive detection of cross-sectional strain and defect structure in an individual Ag five-fold twinned nanowire by 3D electron diffraction mapping

“…Strain and defects, usually coexisting in nanostructures, are known as very important structural factors influencing the mechanical 1 – 4 , electronic and photonic 5 – 7 properties of one-dimensional (1D) nanostructures employed as building blocks for nanoscale devices. Dislocation and disclination are classic examples, and they can result in a characteristic local strain field surrounding themselves 8 – 10 .…”

Auxetic nanomaterials: Recent progress and future development

“…Inspired by the above works on the NPR of metal nanoplates, Kim and collaborators found that the Poisson's ratios of several nanowires not only depend on their sizes via surface stress but also depend on their shape, i.e., the aspect ratio (width to thickness ratio) of the cross-section. 54 For square cross sections, the Poisson's ratios ν xy and ν xz have the same positive value. For rectangular cross sections with the aspect ratio above 1, both ν xy and ν xz are dependent on the applied axial strain.…”