Abstract

A pressure shift of Raman band of liquid water (H₂O) may be an important tool for measuring residual pressures in mineral inclusions, in situ barometry in high-pressure cells, and as an indicator of pressure-induced structural transitions in H₂O. However, there was no consensus as to how the broad and asymmetric water Raman band should be quantitatively described, which has led to fundamental inconsistencies between reported data. In order to overcome this issue, we measured Raman spectra of H₂O in situ up to 1.2 GPa using a diamond anvil cell, and use them to test different approaches proposed for the description of the water Raman band. We found that the most physically meaningful description of water Raman band is the decomposition into a linear background and three Gaussian components, associated with differently H-bonded H₂O molecules. Two of these components demonstrate a pronounced anomaly in pressure shift near 0.4 GPa, supporting ideas of structural transition in H₂O at this pressure. The most convenient approach for pressure calibration is the use of “a linear background + one Gaussian” decomposition (the pressure can be measured using the formula P (GPa) = −0.0317(3)·Δν_G (cm⁻¹), where Δν_G represents the difference between the position of water Raman band, fitted as a single Gaussian, in measured spectrum and spectrum at ambient pressure).

© 2018 The Author(s)

Dynamic high pressure induced strong and weak hydrogen bonds enhanced by pre-resonance stimulated Raman scattering in liquid water

Shenghan Wang, Wenhui Fang, Fabing Li, Nan Gong, Zhanlong Li, Zuowei Li, Chenglin Sun, and Zhiwei Men
Opt. Express 25(25) 31670-31677 (2017)

Estimating the effective pressure from nanosecond laser-induced breakdown in water

Fabing Li, Ying Wang, Haiying Zhao, Xin Xu, Cunming Liu, Zhiwei Men, and Chenglin Sun
Opt. Lett. 46(6) 1273-1276 (2021)

Laser Raman Spectra of Liquid and Solid Bromine and Carbon Disulfide Under High Pressure

A. J. Melveger, J. W. Brasch, and E. R. Lippincott
Appl. Opt. 9(1) 11-15 (1970)

In situ measurements of Raman scattering in clear ocean water

Chuanmin Hu and Kenneth J. Voss
Appl. Opt. 36(27) 6962-6967 (1997)

Raman lidar observations of cloud liquid water

Vincenzo Rizi, Marco Iarlori, Giuseppe Rocci, and Guido Visconti
Appl. Opt. 43(35) 6440-6453 (2004)