Table-top nuclear magnetic resonance system for high-pressure studies with in situ laser heating

Abstract

High pressure Nuclear Magnetic Resonance (NMR) is known to uncover behavior of matter at extreme conditions. However, significant maintenance demands, space requirements and high costs of superconducting magnets render its application unfeasible for regular modern high pressure laboratories. Here, we present a table-top NMR system based on permanent Halbach magnet arrays with dimensions of 25 cm diameter and 4 cm height. At the highest field of 1013 mT, 1 H-NMR spectra of Ice VII have been recorded at 25 GPa and ambient temperature. The table-top NMR system can be used together with double sided laser heating set-ups. Feasibility of high-pressure high-temperature NMR was demonstrated by collecting 1 H-NMR spectra of H2O at 25 GPa and 1063(50) K. We found that the change in signal intensity in laser-heated NMR diamond anvil cell yields a convenient way for temperature measurements.

A Review of the Melting Curves of Transition Metals at High Pressures Using Static Compression Techniques

“…This technique takes advantage of the extreme hardness and the optical properties of diamond, which is transparent in a very wide wavelength range, from gamma and X-rays to mid-infrared, allowing not only laser irradiation but also coupling with various experimental techniques, both in synchrotron facilities and in laboratories. To demonstrate the versatility of the LH-DAC, one can refer to experimental works on X-ray diffraction (XRD) [149][150][151][152][153][154][155][156][157], X-ray absorption (XAS) [158][159][160][161], X-ray fluorescence (XRF) [162], Mössbauer spectroscopy (SMS) [163,164], inelastic X-ray scattering (IXS) [144][145][146], nuclear inelastic scattering (NIS) [165], nuclear magnetic resonance (NMR) [166], and Raman [167][168][169][170][171] and Brillouin [172][173][174][175] spectroscopies or the synthesis of novel materials [176][177][178][179][180][181][182][183]. Different types of diamond anvil cells exist for different applications, but especially for the LH-DAC, the angular opening of the cell is of crucial importance, especially when coupled with experimental techniques such as XRD or Raman/Brillouin spectroscopies, but also when an off-axis laser heating geometry is in place [61].…”

Liquid structure under extreme conditions: high-pressure x-ray diffraction studies

“…High-p liquid-state NMR spectroscopy has been applied predominantly to biochemical studies such as protein folding/unfolding dynamics at up to ∼ 1 GPa [91][92][93][94]. Although NMR spectroscopy is technically feasible in a DAC up to ∼ 100 GPa and ∼ 1050 K [95][96][97], these conditions are generally restricted to solid-state measurements of hydrogen nuclei. The technique could, however, be ideal for studying liquid metallic hydrogen which is predicted under compression even at low T [18,98,99].…”

Refined high-pressure tube design for improved resolution in high-pressure NMR spectroscopy

“…10 A different HP NMR design is the diamond anvil cell, 11 with which ultra-high pressures of up to 202 GPa were reached 12 and that can be used for benchtop applications. 13…”

“…10 A different HP NMR design is the diamond anvil cell, 11 with which ultra-high pressures of up to 202 GPa were reached 12 and that can be used for benchtop applications. 13 Apart from these specialized designs, contemporary developments also utilize simple 14 and miniaturized 15,16 HP systems. However, a HP vessel in shape similar to a standard NMR tube is predominantly employed in commercially available NMR spectrometers.…”