Nuclear magnetic resonance in paramagnetic Mn2P2O7

1969 ◽  
Vol 47 (15) ◽  
pp. 1557-1562 ◽  
Author(s):  
R. J. Atkinson ◽  
C. V. Stager
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Single Crystals ◽  
Room Temperature ◽  
Paramagnetic Shift ◽  
Isotropic Component ◽  
The Magnetic Field ◽  
Nuclear Magnetic

The nuclear magnetic resonance of 31P has been observed in single crystals of Mn2P2O7 at room temperature. The paramagnetic shift of the 31P resonance from γH0 has been determined for rotations of the magnetic field in three principal planes. The isotropic component of the shift indicates the presence of 0.647 ± 0.01% of a single unpaired s electron on the phosphorus ion.

NUCLEAR MAGNETIC RESONANCE IN METAL SINGLE CRYSTALS: I. TIN AND ALUMINUM

1964 ◽  
Vol 42 (8) ◽  
pp. 1499-1507 ◽  
Author(s):  
E. P. Jones ◽  
D. Llewelyn Williams
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Single Crystals ◽  
Knight Shift ◽  
Exchange Interactions ◽  
Indirect Exchange ◽  
Metal Single Crystals ◽  
First Time ◽  
Nuclear Magnetic

Nuclear magnetic resonance studies in single-crystal tin specimens have been done at liquid helium temperatures. The Knight shift has been studied as a function of crystal orientation in a constant magnetic field for different values of field and temperature. The anisotropy of the Knight shift has been observed directly for the first time. The linewidth of the resonance has also been studied and the results indicate a contribution to this from indirect exchange interactions. An attempt has been made to observe oscillations in the Knight shift as a function of magnetic field in both tin and aluminum single crystals. None have been detected but an upper limit to the effect has been set and this is compared with theoretical estimates.

Comparative study of helical-cut notch–coil magnets for fast-field-cycling nuclear magnetic resonance

2014 ◽  
Vol 92 (11) ◽  
pp. 1430-1440 ◽  
Author(s):  
S. Kruber ◽  
G.D. Farrher ◽  
E. Anoardo
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnet System ◽  
Fast Switching ◽  
Magnetic Field Homogeneity ◽  
Field Cycling ◽  
Fast Field ◽  
The Magnetic Field ◽  
Nuclear Magnetic

In this manuscript we describe an α-helical-cut notch–coil magnet system designed for fast switching of the magnetic field. An attempt was made to determine the extent to which such a magnet configuration can be efficiently used for fast-field-cycling (FFC) nuclear magnetic resonance (NMR) instruments. In addition to the typical technical requirements (high field-to-power ratio, adequate electric performance for fast-switching of the magnetic field and NMR-compatible magnetic field homogeneity), a tunable homogeneity within the sample volume and more uniform heat dissipation along the magnet body are included. A helical-cut notch–coil machined in metallic cylinders with external movable pieces was found to fit these requirements very well. A key factor for the optimization of the magnet parameters is the use of a novel calculation procedure based on a more realistic model that consider a magnet geometry with broken azimuthal symmetry. The aim of this paper is to theoretically compare the proposed geometry with other existing designs. No particular prototype is presented here. A clear understanding of the notch–coil performance was found to be an essential step for its further consideration as a potential autoadaptive (electronically controlled) magnet system for FFC applications.

scholarly journals Polarization Transfer via Field Sweeping in Parahydrogen-Enhanced Nuclear Magnetic Resonance

2019 ◽  
Author(s):  
James Eills ◽  
John W. Blanchard ◽  
Teng Wu ◽  
Christian Bengs ◽  
Julia Hollenbach ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Maleic Acid ◽  
Hydrogen Gas ◽  
Zero Field ◽  
Field Sweep ◽  
The Magnetic Field ◽  
Proton Singlet ◽  
Nuclear Magnetic

<div><br></div><div><table><tr><td>We show that in a spin system of two magnetically inequivalent protons coupled to a heteronucleus such as 13C, an adiabatic magnetic field sweep, passing through zero field, transfers proton singlet order into magnetization of the coupled heteronucleus. This effect is potentially useful in parahydrogen-enhanced nuclear magnetic resonance, and is demonstrated on singlet-hyperpolarized [1-13C]maleic acid, which is prepared via the reaction between [1-13C]acetylene dicarboxylic acid and para-enriched hydrogen gas. The magnetic field sweeps are of microtesla amplitudes, and have durations on the order of seconds. We show a polarization enhancement by a factor of 10<sup>4</sup> in the 13C spectra of [1-13C]maleic acid in a 1.4 T magnetic field.</td></tr></table></div>

scholarly journals Methodology for the Permeability Prediction using Spatial Encoding of the Magnetic Field in Nuclear Magnetic Resonance (NMR)

2021 ◽  
Vol 39 (1) ◽  
Author(s):  
José Carlos Xavier da Silva ◽  
Giovanni Chaves Stael ◽  
Silvia Lorena Bejarano Bermudez ◽  
Luis Jacobo Aguilera Aguilera ◽  
Rodrigo Bagueira de Vasconcellos Azeredo
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Spatial Encoding ◽  
Permeability Prediction ◽  
The Magnetic Field ◽  
Nuclear Magnetic

scholarly journals Nuclear magnetic resonance study of the magnetic-field-induced ordered phase in theNiCl2−4SC(NH2)2compound

2017 ◽  
Vol 95 (2) ◽  
Author(s):  
Rémi Blinder ◽  
Maxime Dupont ◽  
Sutirtha Mukhopadhyay ◽  
Mihael S. Grbić ◽  
Nicolas Laflorencie ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Nuclear Magnetic Resonance Study ◽  
Magnetic Resonance Study ◽  
The Magnetic Field ◽  
Nuclear Magnetic

scholarly journals Polarization Transfer via Field Sweeping in Parahydrogen-Enhanced Nuclear Magnetic Resonance

2019 ◽  
Author(s):  
James Eills ◽  
John W. Blanchard ◽  
Teng Wu ◽  
Christian Bengs ◽  
Julia Hollenbach ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Maleic Acid ◽  
Hydrogen Gas ◽  
Zero Field ◽  
Field Sweep ◽  
The Magnetic Field ◽  
Proton Singlet ◽  
Nuclear Magnetic

<div><br></div><div><table><tr><td>We show that in a spin system of two magnetically inequivalent protons coupled to a heteronucleus such as 13C, an adiabatic magnetic field sweep, passing through zero field, transfers proton singlet order into magnetization of the coupled heteronucleus. This effect is potentially useful in parahydrogen-enhanced nuclear magnetic resonance, and is demonstrated on singlet-hyperpolarized [1-13C]maleic acid, which is prepared via the reaction between [1-13C]acetylene dicarboxylic acid and para-enriched hydrogen gas. The magnetic field sweeps are of microtesla amplitudes, and have durations on the order of seconds. We show a polarization enhancement by a factor of 10<sup>4</sup> in the 13C spectra of [1-13C]maleic acid in a 1.4 T magnetic field.</td></tr></table></div>

Nuclear magnetic resonance microscopy

1989 ◽  
Vol 47 ◽  
pp. 828-829
Author(s):  
Paul C. Lauterbur
Keyword(s):  
Magnetic Field ◽  
Nuclear Magnetic Resonance ◽  
Magnetic Resonance ◽  
Magnetic Fields ◽  
Signal To Noise ◽  
Field Gradients ◽  
Useful Signal ◽  
Magnetic Field Gradients ◽  
Observation Times ◽  
Nuclear Magnetic

Nuclear magnetic resonance imaging can reach microscopic resolution, as was noted many years ago, but the first serious attempt to explore the limits of the possibilities was made by Hedges. Resolution is ultimately limited under most circumstances by the signal-to-noise ratio, which is greater for small radio receiver coils, high magnetic fields and long observation times. The strongest signals in biological applications are obtained from water protons; for the usual magnetic fields used in NMR experiments (2-14 tesla), receiver coils of one to several millimeters in diameter, and observation times of a number of minutes, the volume resolution will be limited to a few hundred or thousand cubic micrometers. The proportions of voxels may be freely chosen within wide limits by varying the details of the imaging procedure. For isotropic resolution, therefore, objects of the order of (10μm) may be distinguished.Because the spatial coordinates are encoded by magnetic field gradients, the NMR resonance frequency differences, which determine the potential spatial resolution, may be made very large. As noted above, however, the corresponding volumes may become too small to give useful signal-to-noise ratios. In the presence of magnetic field gradients there will also be a loss of signal strength and resolution because molecular diffusion causes the coherence of the NMR signal to decay more rapidly than it otherwise would. This phenomenon is especially important in microscopic imaging.

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