Mechanical properties of silicon nanowires with native oxide surface state

An analytical-atomistic model for elastic behavior of silicon nanowires

“…In this regard, a velocity of 1.0 Å ps −1 at a temperature of 300 K is employed corresponding to a strain rate of ε ≈ 1.0 × 10 9 s −1 . Such a strain rate falls within the usual range utilized in MD-based NW tensile tests [19,20,30,33]. Atomic stresses are determined by the virial theorem [35].…”

“…To ensure the compatibility between MD simulations and the M-CS method, this study examines Si NWs with circular cross-section only. A length-to-diameter (L/D) ratio of 10 is employed as a suitable limit for examining the elasticity of NWs through MD simulations [19,20,33]. It should be noted that the common cross-sections of Si NWs are typically circular (mostly ⟨111⟩-Si and ⟨112⟩-Si NWs through bottom-up synthesis) or rectangular (mostly ⟨100⟩-Si and ⟨110⟩-Si NWs through top-down manufacturing) [9,19,20].…”

“…A length-to-diameter (L/D) ratio of 10 is employed as a suitable limit for examining the elasticity of NWs through MD simulations [19,20,33]. It should be noted that the common cross-sections of Si NWs are typically circular (mostly ⟨111⟩-Si and ⟨112⟩-Si NWs through bottom-up synthesis) or rectangular (mostly ⟨100⟩-Si and ⟨110⟩-Si NWs through top-down manufacturing) [9,19,20]. The influence of NW cross-sectional shape on elastic properties can be found elsewhere [20].…”

“…In the case of Si NWs, the surface state is commonly observed to be an amorphous silicon dioxide, or native oxide, layer covering Si core [13]. Native oxide is known to have significant effects such as reducing both the stiffness and strength [19,20]. The formation of native oxide is also reported to cause a substantial intrinsic tensile stress up to 1.2 GPa in Si NWs [13].…”