On the use of diamond as a pressure calibrant for near-infrared FT–Raman microspectroscopy at high pressures

Abstract

The pressure-induced shift of the Raman-active t2g phonon mode of the diamond windows in a commercial diamond-anvil cell, located at l332.5 cm−1 at ambient pressure, can be used as an in situ calibrant for near-IR FT–Raman microspectroscopy at high pressures. The measured pressures are considered to be accurate to within ±2 kbar throughout the 4–45 kbar range for which the associated pressure (P, kbar) vs. wavenumber (v, cm−1) relationship is P = 6.66v − 1335.9. Keywords: FT–Raman spectroscopy, diamond, high pressures.