MR021-0008
In-situ characterization of silicon deformation mechanism at high-pressure: comparison between static and dynamic compression
Wednesday, 16 December 2020
Poster
Silvia Pandolfi1,2, Shaughnessy Brennan Brown1, Paul G. Stubley3, Yann Le Godec2, Alexandre Courac2, Andrew Higginbotham4, Cynthia Bolme5, Fang Xu2, Kristina Spektor6, Carlos Renero-Lecuna2, Jean-Paul Itié7, Nicolas Guignot7, Wilson A. Crichton6, Hae Ja Lee1, Bob Nagler1, Eric Galtier1, Wenge Yang8, Richard Sandberg9, Wendy L Mao10, Justin Wark3 and Arianna E Gleason1, (1)SLAC National Accelerator Laboratory, Menlo Park, CA, United States, (2)Sorbonne Université - MNHN - CNRS - IMPMC, Paris, France, (3)University of Oxford, Oxford, United Kingdom, (4)University of York, York, United Kingdom, (5)Los Alamos National Laboratory, Los Alamos, NM, United States, (6)ESRF European Synchrotron Radiation Facility, Grenoble, France, (7)SOLEIL Synchrotron, Gif sur Yvette, France, (8)Center for High Pressure Science and Technology Advanced Research, HPSTAR, Shanghai, China, (9)Brigham Young University, Provo, United States, (10)Stanford-Geological & Env Sci, Stanford, CA, United States
Abstract:
Silicon (Si) is an ideal model system to investigate the properties of planetary materials. The interpretation of experimental results can be simplified thanks to samples of remarkably high purity and low defect density, making precise characterization of Si deformation mechanism viable. Understanding Si behaviour at extreme conditions will help to interpret the response of high-strength and Si-bearing compounds, which are important planetary materials.
Despite an extended experimental effort, the complex behaviour of Si under high pressure is not yet fully understood. In particular, Si deformation under high strain rate (i.e. dynamic compression regime dε/dt∼105-109 s-1) is still a matter of debate, as experimental proofs have been presented supporting both a lowering [1] and an increase [2] of the transition onsets compared to quasi-static loading. Here we present the characterization of Si phase transitions below 20 GPa investigated by in-situ x-ray diffraction during laser-driven shock-compression. Experiments were performed at the Matter in Extreme Conditions End Station at the Linac Coherent Light Source, SLAC, National Accelerator Laboratory.
Exploiting the ultra-fast (sub-picoseconds) temporal resolution, our study captured in-situ the microstructural evolution of shock-compressed single crystalline Si, focusing on the analysis of the transition mechanism and mosaicity evolution. Shock-compression experiments are also compared with quasi-hydrostatic ones performed in a multi-anvil apparatus (i.e. dε/dt∼10-5 s-1), thus providing further insight on the kinetics of these transitions.
[1] EE McBride et al., Phase transition lowering in dynamically compressed silicon, Nature Physics (2019)
[2] RF Smith et al., Orientation and rate dependence in high strain-rate compression of single-crystal silicon, Physical review B (2012)
