Pressure induced structural phase transition in SiC

Gorai, Sanjay Kumar; Bhattacharya, Chandrani; Gundra, Kondayya

doi:10.1063/1.4980189

Cited by 6 publications

(7 citation statements)

References 11 publications

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“… 20 but not ref. 18 Theoretical calculations predict a wide range of stress-density relations for SiC 26 – 33 (Fig. 5 , Supplementary Table 3 ), but it should be noted that our results are in agreement with the recent theoretical calculations of ref.…”

Section: Resultssupporting

confidence: 91%

“…The diamond ramp equation of state 64 and its extrapolation (>800 GPa) are shown as gray dashed curves. b Measured densities of ramp compressed SiC (red circles) and a Birch-Murnaghan (BM) equation of state fit to the reduced isentrope (red curve with assumption of Y = 20 GPa and γ 0 = 1) are compared to the extrapolated EOS of diamond anvil cell experiments (blue 20 and black 18 curves) and the range of densities obtained from first principles calculations (orange shaded region 20 , 26 – 33 , see Supplementary Table 3 ). The gray band shows the pressure-density path along the principal isentrope calculated using the thermodynamic parameters that are listed in the Suppl.…”

Section: Resultsmentioning

confidence: 99%

“…The mass-radius relationship for an Earth-like rocky planet is shown in green. The yellow band represents the mass-radius relationship for a SiC planet using the B1 SiC equation of state from previous studies 18 , 20 , 26 – 33 . The pink band shows the predicted mass-radius relationship for a planet consisting of pure SiC mantle and a Fe or Fe-15Si core (mass fraction of core assumed to be 30%).…”

Section: Discussionmentioning

confidence: 99%

“…Our results show that a pure SiC planet is expected to be ~10% less dense than a MgSiO 3 planet. The mass-radius curves for a pure SiC are also compared with those of (yellow region) using the previously reported B1 EOS 18 , 20 , 26 – 33 shown in Fig. 7 .…”

Section: Discussionmentioning

confidence: 99%

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Structure and density of silicon carbide to 1.5 TPa and implications for extrasolar planets

et al. 2022

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There has been considerable recent interest in the high-pressure behavior of silicon carbide, a potential major constituent of carbon-rich exoplanets. In this work, the atomic-level structure of SiC was determined through in situ X-ray diffraction under laser-driven ramp compression up to 1.5 TPa; stresses more than seven times greater than previous static and shock data. Here we show that the B1-type structure persists over this stress range and we have constrained its equation of state (EOS). Using this data we have determined the first experimentally based mass-radius curves for a hypothetical pure SiC planet. Interior structure models are constructed for planets consisting of a SiC-rich mantle and iron-rich core. Carbide planets are found to be ~10% less dense than corresponding terrestrial planets.

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Section: Resultssupporting

confidence: 91%

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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Structure and density of silicon carbide to 1.5 TPa and implications for extrasolar planets

et al. 2022

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“…The phase transition of SiC under extreme conditions is relevant for studying carbon-rich exoplanets 32 and superhard materials 33 , where the transition from the zinc blende (3C) to the rock salt (RS) phase is observed at high pressure from experiments 32,[34][35][36][37][38][39] and ab initio calculations [40][41][42][43][44][45][46][47] . Empirical potentials such as Tersoff 48,49 , Vashishta 50,51 , MEAM 52 , and Gao-Weber 53 have been developed and applied in large-scale simulations for different purposes.…”

Section: Introductionmentioning

confidence: 99%

Uncertainty-aware molecular dynamics from Bayesian active learning for Phase Transformations and Thermal Transport in SiC

Xie¹,

Vandermause²,

Ramakers³

et al. 2022

Preprint

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Machine learning interatomic force fields are promising for combining high computational efficiency and accuracy in modeling quantum interactions and simulating atomic level processes.Active learning methods have been recently developed to train force fields efficiently and automatically. Among them, Bayesian active learning utilizes principled uncertainty quantification to make data acquisition decisions. In this work, we present an efficient Bayesian active learning workflow, where the force field is constructed from a sparse Gaussian process regression model based on atomic cluster expansion descriptors. To circumvent the high computational cost of the sparse Gaussian process uncertainty calculation, we formulate a high-performance approximate mapping of the uncertainty and demonstrate a speedup of several orders of magnitude. As an application, we train a model for silicon carbide (SiC), a wide-gap semiconductor with complex polymorphic structure and diverse technological applications in power electronics, nuclear physics and astronomy. We show that the high pressure phase transformation is accurately captured by the autonomous active learning workflow. The trained force field shows excellent agreement with both ab initio calculations and experimental measurements, and outperforms existing empirical models on vibrational and thermal properties. The active learning workflow is readily generalized to a wide range of systems, accelerates computational understanding and design.

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Comparative study on mechanical properties of three different SiC polytypes (3C, 4H and 6H) under high pressure: First-principle calculations

Peivaste

Alahyarizadeh

Minuchehr

et al. 2018

Vacuum

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Pressure induced structural phase transition in SiC

Cited by 6 publications

References 11 publications

Structure and density of silicon carbide to 1.5 TPa and implications for extrasolar planets

Structure and density of silicon carbide to 1.5 TPa and implications for extrasolar planets

Uncertainty-aware molecular dynamics from Bayesian active learning for Phase Transformations and Thermal Transport in SiC

Comparative study on mechanical properties of three different SiC polytypes (3C, 4H and 6H) under high pressure: First-principle calculations

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