Insights into the mechanical properties and fracture mechanism of Cadmium Telluride nanowire

TL;DR

This study uses molecular dynamics simulations to analyze the mechanical properties and fracture mechanisms of Cadmium Telluride nanowires, revealing orientation-dependent strengths, new failure modes, and effects of size, temperature, and strain rate.

Contribution

It provides novel insights into the fracture behavior of [111]-oriented CdTe nanowires, including the discovery of void formation as a failure mechanism under tension.

Findings

[111]-oriented NWs have higher tensile strength than [110]-oriented NWs.

Void formation is observed as a new failure mechanism under tension.

Higher strain rates increase fracture strength and void formation.

Abstract

The mechanical properties of Cadmium telluride (CdTe) nanowire have become focus of interest now-a-days due to its promising application in opto-electro-mechanical nanodevices. Inthis study, molecular dynamics simulations have been used to investigate the mechanical behavior of Zinc Blende (ZB) crystal structured CdTe nanowires (NWs) by varying size, temperature, crystal orientation and strain rate under tension and compression. Results show that the fracture strength of the [111]-oriented CdTe NWs is always higher than that of the [110]-oriented CdTe NWs under tension whereas in compression, the fracture strength of the [111]-oriented CdTe NWs is significantly lower than that of the [110]-oriented CdTe NWs. Moreover, under tensile load, void in ZB [111]-oriented CdTe NWs has been observed which is a new failure mechanism found in this study. It has also been observed that size has negligible effect on the tensile behavior but in compression the behavior is clearly size dependent. Both tensile and compressive strengths show an inverse relation with temperature. When tensile load is applied along NWs growth direction, the [111]-oriented CdTe NWs fail by creating void in [10-1] direction regardless of temperature and NW size. Under compression, the [111]-oriented nanowire show buckling and plasticity. Finally, the impact of strain rate on [111]-oriented ZB CdTe NWs is also studied where higher fracture strengths and strains at a higher strain rates have been found under both tension and compression. With increasing the strain rate, the number of voids is also increased in the NWs.This study will help to design CdTe NWs based devices efficiently by presenting in-depth understanding of failure behavior of the [111]-oriented CdTe NWs.