Mechano-freezing of the ambient water

TL;DR

This study investigates the pressure-induced freezing of ambient water using Raman spectroscopy, revealing phase transitions, phonon shifts, and inter-electron-pair interactions under compression.

Contribution

It provides new insights into the mechano-freezing process of water and the associated phonon behavior under high pressure conditions.

Findings

Transition from 1.35 GPa to 0.86 GPa during freezing

Blue shift of high-frequency phonon (~3120 cm-1)

Stiffening of low-frequency phonons (~200 cm-1)

Abstract

Raman spectroscopy examination of the 25 deg-C water freezing under compression revealed transition from 1.35 GPa to 0.86 GPa upon ice being formed at continued volume change. The transition is associated with a slight blue shift of the high-frequency phonon (omiga_H ~ 3120 cm-1) and creation of the low-frequency phonons (Omiga_L ~ 200 cm-1). In the liquid and in the solid phase, the increased pressure softens the Omiga_H and stiffens the Omida_L, which indicates the presence of the inter-electron-pair repulsion in both liquid and solid water.