In‐situRaman study of phengite compressed in water medium under simultaneously highP–Tparameters

Abstract

The in‐situ method of Raman spectroscopy was used to study the layered mineral phengite, K(Al,Mg)2(Si,Al)4O10(OH)2, compressed in water under simultaneously high temperatures and pressures (respectively, up to 373 °С and 12.5 GPa). The implemented conditions were typical of modeling the ‘cold’ subduction zones in lithospheric slabs. The high pressures and temperatures were produced in an electrically heated diamond‐anvil cell. Measured Raman spectra have demonstrated a high Р–Т stability of the mineral. No non‐quenchable phengite states (no reversible or irreversible polymorphic transitions, overhydration or notable amorphization) were observed in the investigated samples. Copyright © 2017 John Wiley & Sons, Ltd.

In situ micro-FTIR spectroscopic investigations of synthetic ammonium phengite under pressure and temperature

“…Furthermore, we studied its vibrational response to compression up to 42 GPa at ambient T in diamond anvil cell (DAC) experiments. These data are compared with recent studies on the devolatilisation of natural phengite containing trace amounts of NH + 4 (Liu et al, 2019;Yang et al, 2017) and with our own experimental results as well as with existing data (Goryainov et al, 2017;Zhang et al, 2010) on the dehydration of synthetic and natural ammonium-free phengite. NH 4 -endmember phengite is not reported from natural rocks so far.…”

“…The lattice modes of phengite have been assigned by means of IR and Raman spectroscopy (e.g. Goryainov et al, 2017;McKeown et al, 1999). In addition to the lattice modes, other vibrational modes in NH 4 -phengite come from the NH + 4 molecule located at the interlayer cation site, as well as from the OH situated in the octahedral layer (OH stretching vibration).…”

Recent advances in linear and nonlinear Raman spectroscopy. Part XII

“…Goryainov et al carried out an in‐situ Raman study of phengite compressed in water medium under simultaneously high P–T parameters. The high pressures and temperatures were produced in an electric heated diamond anvil cell, and the measured Raman spectra demonstrated a high P–T stability of the mineral . Guo et al reported a comparative investigation of the vibrational properties of bulk 2H ‐MoS 2 and its exfoliated nanosheets under high pressure.…”

“…The high pressures and temperatures were produced in an electric heated diamond anvil cell, and the measured Raman spectra demonstrated a high P-T stability of the mineral. [204] Guo et al reported a comparative investigation of the vibrational properties of bulk 2H-MoS 2 and its exfoliated nanosheets under high pressure. The systematic research about the 2LA (M) in bulk 2H-MoS 2 suggests that the high-pressure behavior of this double resonance Raman mode arises from the pressure-induced metalization and band gap closure.…”

GeoRaman

“…Petrov calibrated the peak positions, half widths, and peak intensities of methane Raman bands with the goal of using this calibration to accurately determine the pressure of methane‐containing media. Behavior of phengitic mica at high‐pressure and ‐temperature conditions, typical for “cold” subduction zone, was analyzed by Goryainov et al. The pressure dependence of Raman bands for alkaline carbonate (nyerereite) was obtained by Rashchenko et al in order to estimate residual pressure values for melt inclusions in olivine from sheared garnet peridotites, one of the deepest mantle xenoliths.…”