Tunable Mechanics and Micromechanism in Close-Knit Silicide-inSiO2 Core-Shell Nanowires

Bending/tension mechanics is one of the core issues for nanowires in flexible free-standing transport and sensor applications, but it remains a challenge to tailor the mechanical performance beyond the inherent properties. Herein, based on structure engineering, silicon-based Mn5Si3@SiO2 nanocables are proposed and demonstrated as versatile nanosystems. Except for outstanding toughness, large ultimate strain, and great strength, they display diverse mechanical behaviors such as simplex elasticity, plasticity, and viscoelasticity under different external conditions. The tunable performances originate from synergetic effects between the core and shell components, like the atomic bonding transitional interface and space confinement, which induce optimizing internal stress distribution and the dislocation evolution mechanism in the core. The related mechanical performance is revealed carefully. The bending and tension dynamic picture, quantitative force curve, stressstrain dependence, and the corresponding lattice evolution are acquired by in/ex situ characterizations and measurements. These results contribute to nanowire mechanical design and also expand to strain-regulated three-dimensional multifunctional nanosystems.

Automated summary

This study demonstrates the design of silicon-based Mn5Si3@SiO2 nanocables through structure engineering, exhibiting diverse mechanical behaviors under different external conditions, including simplex elasticity, plasticity, and viscoelasticity. These tunable performances originate from the synergetic effects between the core and shell components, optimizing internal stress distribution and the dislocation evolution mechanism. The findings are significant for nanowire mechanical design and the expansion of strain-regulated three-dimensional multifunctional nanosystems.