Dynamical Instability Causes the Demise of a Supercooled Tetrahedral Liquid

Abstract

We investigate the relaxation mechanism of a supercooled tetrahedral liquid at its limit of stability using isothermal isobaric (N P T ) Monte Carlo (MC) simulations. In similarity with systems which are far from equilibrium but near the onset of jamming [O'Hern et.al., Phys. Rev. Lett is a relatively rapid crystallization due to lack of long-wavelength fluctuations and the instability at φ mid , i.e., the condition that G decreases as configurations with potential energies lower than φ mid are accessed. The dynamical crossover point and the associated change in the time-scale of fluctuations is found to be consistent with the previous studies.

Cooperative freezing of the L12 ordered domains at the critical cooling temperature of Ni3Fe alloy

“…That there is something unique about T c (apart from the phenomena elaborated above) is also highlighted by the fact that average fractions of Ni(L12 1), Ni(L12 4) (see figure 5), Fe(L12 1) (figure 8), Fe(1) (figure 9), Fe(2), Fe(3) (figure 11), the LROP (figure 6), and the ratios R1, R2, R3 (figure 12) are in close agreement (at T c or T r = 1) for ADP and EAM simulated alloys. The physical phenomena involved here appears to be qualitatively similar to the cooperative freezing of the four-coordinated amorphous networks across the limit of stability of a supercooled tetrahedral liquids [43,44]. With regard to the changes at an atomistic level, we find that the Ni([IP]3) atoms together with nearest neighbours constitute about 75% of the total atoms at T c , which suggest a significant role of these atoms in the ordering process through propagation.…”

Topological Identification Criteria, Stability, and Relevance of Pentagonal Nanochannels in Amorphous Ice

“…In this work, we generated trajectories in isothermal–isobaric ( NPT ) molecular dynamics (MD) simulation of supercooled mW water. The relaxation was analyzed in an isothermal trajectory at 205 K corresponding to the limit of stability at zero pressure. ,− We used a system size of 125 000 particles. We also used a MD cooling trajectory (using a system size of 140 608 particles) at the rate of 0.1 K/ns and analyzed the amorphous state obtained at 150 K. The trajectory was generated using LAMMPS .…”

“…Following the earlier studies, , we consider two particles to be “bonded” if the distance between the particles is less than or equal to 1.4. Throughout this work, unless it is stated explicitly, we use reduced units in terms of mW potential parameters ϵ and σ.…”