Homogeneous crystal nucleation in liquid copper under quasi-isentropic compression

Abstract

Shock-induced freezing in liquids has long been a subject of interest as well as mystery. With large-scale molecular dynamics simulations, we demonstrate that homogeneous crystal nucleation in liquid Cu can be realized under certain supercooling (θ), via quasi-isentropic compression or ramp wave loading with a particle velocity u p achieved within a ramp time τ . The simulations yield the τ -u p -θ relations for homogeneous crystallization at the spatial and temporal scales of molecular dynamics; a ramp wave loading with τ ∼ 100 ps is essentially isentropic for liquid Cu. Based on classical nucleation theory, we predict θ, and thus u p , as required for homogenous nucleation in experiments with larger length and time scales. Homogeneous nucleation can also be achieved with shock loading in initially sueprcooled liquids.

Catalysis of partial chiral symmetry restoration by Δ matter

“…We also showed that the matter constituents change significantly with the finite isospin chemical potentials. In asymmetric matter, ∆ − appears first similarly to the ones obtained in the neutron star analyses [15][16][17][18].…”

“…In this N -∆ matter, the effective masses of ∆ and N are close to each other as in Eq. (17). Since ∆ has sixteen degrees of freedom (spin 3/2 and isospin 3/2) compared with four (spin 1/2 and isospin 1/2) for nucleon, the ∆ density could be larger than N density.…”

“…Then, one can easily see that ∆ − enters the matter first among the four ∆ baryons as in Refs. [13,[15][16][17][18]. In Fig.…”

“…It was shown that there can be instabilities when ∆ matter appears. There are also many works on the ∆ baryons in neutron stars [14][15][16][17][18]. It was pointed that the ∆ baryon enters into the matter around two to three times of the normal nuclear matter density ρ 0 .…”

Tensile Strength of Liquids: Equivalence of Temporal and Spatial Scales in Cavitation

“…Although only two cases, that is, cavitation of LJ and Cu liquids, are considered here, the equivalence between temporal and spatial scales is likely common for any physical processes that involve nucleation of a new "phase" and hence should apply to a variety of processes for many materials, including chemical reactions, plasticity, melting and crystallization. 47 Equation 6 is quite general and can be used to make upward or downward extrapolations from one scale to another, either in time or in space.…”