Phase transitions and elastic anisotropies of SiC polymorphs under high pressure

Structural, Electronic, and Mechanical Properties of Ag‐Cu‐Ga Intermetallic Compounds: First‐Principles Calculations

“…While if B/G is >1.75, the material should be ductile. [ 35 ] Figure shows Cauchy pressure (C 12 ‐ C 44 ) and the B / G ratio as a function of pressure. For Ag 2 Ga and CuGa 2 , the values of C 12 ‐ C 44 is positive at pressures of 0–20 GPa, and the B/G ratio is >1.75.…”

Pressure and temperature stability boundaries of cubic SiC polymorphs: a first-principles investigation

“…No evidence of dynamic instabilities was found in either of the two phases up to 100 GPa. The recent results of Ran et al 17 based on explicit elastic constant calculations showed mechanical instability of the B3 phase at 112 GPa. Although the impossibility of even a metastable 3C-SiC-B3 phase at pressures above 112 GPa is deduced from these calculations, we would like to make clear that we have not found any indication relating this instability to a softening mechanism involved in the B3 to B1 transition, which is not surprising in the context of a reconstructive transition.…”

“…Our view of this reconstructive B3–B1 transition does not take into account the well-known mechanical stability criteria (involved in displacive transformations) recently applied by Ran et al , 17 since the energetic barriers and the hysteresis of the transformation are here the key factors affecting the observed pressure values for the direct and reverse B3–B1 transitions. Overall, computer simulations are in this regard very convenient since they can separate thermodynamic boundaries (usually less complicated to evaluate) from kinetic effects involving transition mechanisms and the time evolution of atomic displacements (see the two first chapters of ref.…”

Uncertainty-aware molecular dynamics from Bayesian active learning for phase transformations and thermal transport in SiC

“…In particular, SiC has been identified from the adsorption spectroscopy of carbon-rich extrasolar planets 23,24 , which has motivated numerous experimental and computational studies of its high temperature high pressure behavior. The phase transition of SiC from the zinc blende (3C) to the rock salt (RS) phase is observed at high pressure in experiments [25][26][27][28][29][30][31] and ab initio calculations [32][33][34][35][36][37][38][39] . Empirical potentials such as Tersoff 40,41 , Vashishta 42,43 , MEAM 44 , and Gao-Weber 45 have been developed and applied in large-scale simulations for different purposes.…”