Enabling Natural Abundance 17O Solid-State NMR by Direct Polarization from Paramagnetic Metal Ions
Autor: | Daniel Jardón-Álvarez, Michal Leskes, Guy Reuveni, Adi Harchol |
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Rok vydání: | 2020 |
Předmět: |
Titanium
Letter Magnetic Resonance Spectroscopy Materials science Iron Relaxation (NMR) Oxides 02 engineering and technology Nuclear magnetic resonance spectroscopy Oxygen Isotopes 010402 general chemistry 021001 nanoscience & nanotechnology Polarization (waves) 7. Clean energy 01 natural sciences 0104 chemical sciences NMR spectra database Paramagnetism Solid-state nuclear magnetic resonance Chemical physics Spin diffusion General Materials Science Hyperpolarization (physics) Physical and Theoretical Chemistry 0210 nano-technology |
Zdroj: | The Journal of Physical Chemistry Letters |
ISSN: | 1948-7185 |
Popis: | Dynamic nuclear polarization (DNP) significantly enhances the sensitivity of nuclear magnetic resonance (NMR), increasing its applications and the quality of NMR spectroscopy as a characterization tool for materials. Efficient spin diffusion among the nuclear spins is considered to be essential for spreading the hyperpolarization throughout the sample, enabling large DNP enhancements. This scenario mostly limits the polarization enhancement of low-sensitivity nuclei in inorganic materials to the surface sites when the polarization source is an exogenous radical. In metal-ion-based DNP, the polarization agents are distributed in the bulk sample and act as a source of both relaxation and polarization enhancement. We have found that as long as the polarization agent is the main source of relaxation, the enhancement does not depend on the distance between the nucleus and dopant. As a consequence, the requirement of efficient spin diffusion is lifted, and the entire sample can be directly polarized. We exploit this finding to measure high-quality NMR spectra of 17O in the electrode material Li4Ti5O12 doped with Fe(III) despite its low abundance and long relaxation time. |
Databáze: | OpenAIRE |
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