Does the Sastry transition control cavitation in simple liquids?

TL;DR

This study investigates how the Sastry transition influences cavitation in simple liquids with various interaction ranges, revealing that vibrational and entropic factors mainly govern cavitation barriers, except in long-range interacting liquids.

Contribution

It provides a detailed analysis of the Sastry transition's role in cavitation across different pair potentials and identifies the dominant factors affecting cavitation barriers in simple liquids.

Findings

Cavitation barriers are mainly vibrational and entropic in typical simple liquids.

Long-range interactions like in alkali metals may deviate from this trend.

The Sastry transition's influence varies with interaction range and temperature.

Abstract

We examine the Sastry (athermal cavitation) transitions for model monatomic liquids interacting via Lennard-Jones as well as shorter- and longer-ranged pair potentials. Low-temperature thermodynamically stable liquids have $\rho < \rho_S$ except when the attractive forces are long-ranged. For moderate- and short-ranged attractions, stable liquids with $\rho > \rho_S$ exist at higher temperatures; the pressures in these liquids are high, but the Sastry transition may strongly influence their cavitation under dynamic hydrostatic expansion. The temperature $T^*$ at which stable $\rho > \rho_S$ liquids emerge is $\sim 0.84\epsilon/k_B$ for Lennard-Jones liquids; $T^*$ decreases (increases) rapidly with increasing (decreasing) pair-interaction range. In particular, for short-ranged potentials, $T^*$ is above the critical temperature. All liquids' inherent structures are isostructural (isomorphic) for densities below (above) the Sastry density $\rho_S$. Overall, our results suggest that the barriers to cavitation in most simple liquids under ambient conditions where significant cavitation is likely to occur are primarily vibrational-energetic and entropic rather than configurational-energetic. The most likely exceptions to this rule are liquids with long-ranged pair interactions, such as alkali metals. The most likely exceptions to this rule are liquids with long-ranged pair interactions, such as alkali metals.