Atomistic deformation mechanism of silicon under laser-driven shock compression

Silvia Pandolfi; S Brennan Brown; P G Stubley; Andrew Higginbotham; C A Bolme; H J Lee; B Nagler; E Galtier; R L Sandberg; W Yang; W L Mao; J S Wark; A E Gleason

doi:10.1038/s41467-022-33220-0

Atomistic deformation mechanism of silicon under laser-driven shock compression

Nat Commun. 2022 Sep 21;13(1):5535. doi: 10.1038/s41467-022-33220-0.

Authors

Silvia Pandolfi¹, S Brennan Brown², P G Stubley³, Andrew Higginbotham⁴, C A Bolme⁵, H J Lee², B Nagler², E Galtier², R L Sandberg^{5

6}, W Yang⁷, W L Mao⁸, J S Wark³, A E Gleason²

Affiliations

¹ SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA, 94025, USA. silviap@stanford.edu.
² SLAC National Accelerator Laboratory, 2575 Sand Hill Rd., Menlo Park, CA, 94025, USA.
³ Department of Physics, Clarendon Laboratory, Univeristy of Oxford, Parks Road, Oxford, OX1 3PU, UK.
⁴ Department of Physics, University of York, Heslington York, YO10 5DD, UK.
⁵ Los Alamos National Laboratory, Los Alamos, NM, 87545, USA.
⁶ Department of Physics and Astronomy, Brigham Young University, Provo, UT, 84602, USA.
⁷ Center for High Pressure Science and Technology Advanced Research (HPSTAR), Shanghai 201203, China.
⁸ Geological Sciences, Stanford University, 367 Panama St., Stanford, CA, 94305, USA.

Abstract

Silicon (Si) is one of the most abundant elements on Earth, and it is the most widely used semiconductor. Despite extensive study, some properties of Si, such as its behaviour under dynamic compression, remain elusive. A detailed understanding of Si deformation is crucial for various fields, ranging from planetary science to materials design. Simulations suggest that in Si the shear stress generated during shock compression is released via a high-pressure phase transition, challenging the classical picture of relaxation via defect-mediated plasticity. However, direct evidence supporting either deformation mechanism remains elusive. Here, we use sub-picosecond, highly-monochromatic x-ray diffraction to study (100)-oriented single-crystal Si under laser-driven shock compression. We provide the first unambiguous, time-resolved picture of Si deformation at ultra-high strain rates, demonstrating the predicted shear release via phase transition. Our results resolve the longstanding controversy on silicon deformation and provide direct proof of strain rate-dependent deformation mechanisms in a non-metallic system.

Abstract

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