Role of Surface Reconstructions in (111) Silicon Fracture

Fernández‐Torre, Delia; Albaret, Tristan; Vita, Alessandro De

doi:10.1103/physrevlett.105.185502

Cited by 14 publications

(17 citation statements)

References 18 publications

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“…Moreover, as brittle cleavage proceeds through thermodynamic energy balance, it is usually argued that the relevant surface energy is the as-cleaved surface energy 17 . For a surface reconstruction to be relevant to determining the energy balance for fracture, it must form instantaneously from the propagating crack tip 34 . The geometry relaxations we performed allow us to exclude barrierless surface reconstructions.…”

Section: Methodsmentioning

confidence: 99%

In situ stable crack growth at the micron scale

et al. 2017

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Grain boundaries typically dominate fracture toughness, strength and slow crack growth in ceramics. To improve these properties through mechanistically informed grain boundary engineering, precise measurement of the mechanical properties of individual boundaries is essential, although it is rarely achieved due to the complexity of the task. Here we present an approach to characterize fracture energy at the lengthscale of individual grain boundaries and demonstrate this capability with measurement of the surface energy of silicon carbide single crystals. We perform experiments using an in situ scanning electron microscopy-based double cantilever beam test, thus enabling viewing and measurement of stable crack growth directly. These experiments correlate well with our density functional theory calculations of the surface energy of the same silicon carbide plane. Subsequently, we measure the fracture energy for a bi-crystal of silicon carbide, diffusion bonded with a thin glassy layer.

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Section: Methodsmentioning

confidence: 99%

In situ stable crack growth at the micron scale

et al. 2017

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“…Nevertheless, graphene is not immune to defect. Any defect that deforms the structure of the original honeycomb lattice has a strong impact in the electronic properties of graphene [14][15][16][17][18][19][20][21][22]. For example, lattice deformation of graphene will introduce effective gauge fields and influence the Dirac fermions in graphene like an effective magnetic field [14,15,23].…”

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confidence: 99%

Electronic structures of graphene layers on a metal foil: The effect of atomic-scale defects

Yan

Liu

Bai

et al. 2013

Applied Physics Letters

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Here, we report a facile method to generate a high density of atomic-scale defects in graphene on metal foil and show how these defects affect the electronic structures of graphene layers. Our scanning tunneling microscope measurements, complemented by first-principles calculations, reveal that the atomic-scale defects result in both the intervalley and intravalley scattering of graphene. The Fermi velocity is reduced in the vicinity area of the defect due to the enhanced scattering.

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“…Previous work 16 has revealed that at speeds below about 1,000 ms À 1 , a crack-tip reconstruction consisting of a five-and seven-membered ring related to the p-bonded Pandey 2 Â 1 reconstruction of the (111) surface 28 forms spontaneously. Because of the broken mirror symmetry of the crystal with respect to {111} planes, the five-seven crack tip reconstruction can form on only one of the two fracture surfaces 27 , the lower surface with respect to the axes of Fig. 1, meaning that successive tip reconstruction events can build up to form large-scale surface features via a positive feedback sinking process 16 .…”

Section: Resultsmentioning

confidence: 99%

“…1a). As was done in many previous studies 6,7,[14][15][16][17][18]27 , periodic boundary conditions were used along the crack front direction, a fully threedimensional investigation being, for now, out of reach of DFT-based atomistic simulations. Previous work 16 has revealed that at speeds below about 1,000 ms À 1 , a crack-tip reconstruction consisting of a five-and seven-membered ring related to the p-bonded Pandey 2 Â 1 reconstruction of the (111) surface 28 forms spontaneously.…”

Section: Resultsmentioning

confidence: 99%

Macroscopic scattering of cracks initiated at single impurity atoms

et al. 2013

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Brittle crystals, such as coloured gems, have long been known to cleave with atomically smooth fracture surfaces, despite being impurity laden, suggesting that isolated atomic impurities do not generally cause cracks to deflect. Whether cracks can ever deviate when hitting an atomic defect, and if so how they can go straight in real brittle crystals, which always contain many such defects, is still an open question. Here we carry out multiscale molecular dynamics simulations and high-resolution experiments on boron-doped silicon, revealing that cracks can be deflected by individual boron atoms. The process, however, requires a characteristic minimum time, which must be less than the time spent by the crack front at the impurity site. Deflection therefore occurs at low crack speeds, leading to surface ridges which intensify when the boron-dopage level is increased, whereas fast-moving cracks are dynamically steered away from being deflected, yielding smooth cleavage surfaces.

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Role of Surface Reconstructions in (111) Silicon Fracture

Cited by 14 publications

References 18 publications

In situ stable crack growth at the micron scale

In situ stable crack growth at the micron scale

Electronic structures of graphene layers on a metal foil: The effect of atomic-scale defects

Macroscopic scattering of cracks initiated at single impurity atoms

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