Raman Spectroscopy at High Pressures

Abstract

Raman spectroscopy is one of the most informative probes for studies of material properties under extreme conditions of high pressure. The Raman techniques have become more versatile over the last decades as a new generation of optical filters and multichannel detectors become available. Here, recent progress in the Raman techniques for high-pressure research and its applications in numerous scientific disciplines including physics and chemistry of materials under extremes, earth and planetary science, new materials synthesis, and high-pressure metrology will be discussed.

A Brief Review of the Effects of Pressure on Wolframite-Type Oxides

“…Although, according to the ionic radius of Cu, it should also crystallize in the same structure as NiWO4 and ZnWO4, it does it in a distorted version of the wolframite structure. In CuWO4, as a consequence of the Jahn-Teller effect of Cu 2+ in octahedral coordination [23,24], the Cu 2+ ion requires a distortion that is achieved by a shear parallel to the b-axis along each copper plane. This has as a consequence a displacement of oxygen layers, destroying the twofold symmetry and lowering the space group from P2/c to P1 � .…”

“…Raman spectroscopy is a technique used to observe vibrational modes in a solid and is one of the most informative probes for studies of material properties under HP [24]. Since the study performed two decades ago by Fomichev et al in ZnWO 4 and CdWO 4 [25], the Raman spectra of wolframite-type tungstates have been extensively characterized.…”

Brief Review of the Effects of Pressure on Wolframite-Type Oxides

“…Despite, according to the ionic radius of Cu, it should also crystallize in the same structure as NiWO4 and ZnWO4, it does it in a distorted version of the wolframite structure. In CuWO4, as a consequence of the Jahn-Teller effect of Cu 2+ in octahedral coordination [23,24], the Cu 2+ ion requires a distortion which is achieved by a shear parallel to the b axis along each copper plane. This has as a consequence a displacement of the oxygen layers with each other destroying the twofold symmetry and lowering the space group from P2/c to P1 .…”

“…Raman spectroscopy is a technique used to observe vibrational modes in a solid being one of the most informative probes for studies of material properties under highpressure [24]. Since the study performed two decades ago by Fomichev et al in ZnWO4 and CdWO4 [25] the Raman spectra of wolframite-type tungstates have been extensively characterized.…”

Molecular response of liquid nitrogen multiply shocked to 40 GPa

“…28 Raman measurements are routinely used to characterize intramolecular bonding changes, and to determine the roles of pressure and temperature on such changes. 28,29 However, accurate determination of temperatures achieved in shock compressed materials remains a significant challenge.…”