Fig. 3: 1H-NMR spectra of all sample systems.
From: Structural independence of hydrogen-bond symmetrisation dynamics at extreme pressure conditions
a High-resolution 2D-Lee Goldburg (LG) spectrum of δ-(Al0.3,Fe0.7)OOH at 15.7 GPa showing up to six distinguishable hydrogen signals in the indirect LG projection F220. Assuming a stochastic distribution of ferric iron in the sample, a comparison with signal intensities allows for the assignment of the H-bond species Qi(i = 1–6). Spectra at different pressures were recorded at reduced resolution due to experimental time restrictions and solely signals from Q3, Q5 and Q6 species were recorded over the full pressure range. The integration limits for 2D signal intensity determination were defined by 35 kHz in the direct time domain F1 and by the FWHM of each signal in the indirect LG-projection dimension F2. The colored regions are guide to the eyes and do not correspond to the integration limits. b High-resolution 2D-LG spectra of dense magnesium silicate phase-D, showing a shift towards lower chemical shifts at the HS → LS crossover (Fig. 4a). Measurements were conducted at a magnetic field of 7.04 T. 1H-NMR solid-echos of c δ-AlOOH and d H2O ice-VII/X as a function of pressure. Measurements were conducted at a magnetic field of 1.2 T. Figures a and b are reproduced from ref. 20; licensed under a Creative Commons Attribution (CC BY) license.
