Abstract: An experimental method is described allowing fast field-cycling Nuclear Magnetic Resonance (NMR) experiments over wide range of magnetic fields from 5 nT to 10 T. The method makes use a hybrid technique: the high field range is covered by positioning the sample in the inhomogeneous stray field of the NMR spectrometer magnet. For fields below 2 mT a magnetic shield is mounted on top to the spectrometer; inside the shield the magnetic field is controlled by a specially designed coil system. This combination allows us to measure T1-relaxation times and nuclear Overhauser effect parameters over the full range in a routine way. For coupled proton-carbon spin systems relaxation with a common T_1 is found at low fields, where the spins are "strongly coupled". In some cases, experiments at ultralow fields provide access to heteronuclear long-lived spin states. Efficient coherent polarization transfer is seen for proton-carbon spin systems at ultralow fields as follows from the observation of quantum oscillations in the polarization evolution. Applications to analysis and manipulation of heteronuclear spin systems are discussed.

Cite: Zhukov I.V. , Kiryutin A.S. , Yurkovskaya A.V. , Grishin Y.A. , Vieth H-M. , Ivanov K.L.
Field-cycling NMR experiments in ultra-wide magnetic field range: relaxation and coherent polarization transfer
Physical Chemistry Chemical Physics. 2018. V.20. N18. P.12396-12405. DOI: 10.1039/C7CP08529J

Dates:

Submitted:	Dec 20, 2017
Accepted:	Mar 15, 2018
Published online:	Mar 21, 2018

Identifiers: No identifiers

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