1H-Detected quadrupolar spin–lattice relaxation measurements under magic-angle spinning solid-state NMR

2019 ◽  
Vol 55 (39) ◽  
pp. 5643-5646 ◽  
Author(s):  
Maria Makrinich ◽  
Amir Goldbourt
Keyword(s):  
Solid State Nmr ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Magic Angle Spinning ◽  
Spin Lattice Relaxation ◽  
Magic Angle ◽  
Proton Detection ◽  
Spin Lattice ◽  
Relaxation Measurements ◽  
Angle Spinning

Proton detection and phase-modulated pulse saturation enable the measurement of spin–lattice relaxation times of “invisible” quadrupolar nuclei with extensively large quadrupolar couplings.

scholarly journals Exploring the Role of Phosphate Structural Distortions on the Sodium Jump Dynamics in NASICON Phases

2015 ◽  
Vol 1773 ◽  
pp. 1-6
Author(s):  
Todd M. Alam ◽  
Nelson Bell ◽  
Jill Wheeler ◽  
Erik D. Spoerke ◽  
Randall T. Cygan ◽  
...  
Keyword(s):  
Sol Gel ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Magic Angle Spinning ◽  
Spin Lattice Relaxation ◽  
Magic Angle ◽  
Spin Lattice ◽  
Relaxation Experiments ◽  
Jump Dynamics ◽  
Angle Spinning

ABSTRACTHigh temperature solid state sodium (23Na) magic angle spinning (MAS) NMR spin lattice relaxation times (T1) were evaluated for a series of NASICON (Na3Zr2PSi2O12) materials to directly determine Na jump rates. Simulations of the T1 temperature variations that incorporated distributions in Na jump activation energies, or distribution of jump rates, improved the agreement with experiment. The 23Na NMR T1 relaxation results revealed that distributions in the Na dynamics were present for all of the NASICON materials investigated here. The 23Na relaxation experiments also showed that small differences in material composition and/or changes in the processing conditions impacted the distributions in the Na dynamics. The extent of the distribution was related to the presence of a disordered or glassy phosphate phase present in these different sol-gel processed materials. The 23Na NMR T1 relaxation experiments are a powerful tool to directly probing Na jump dynamics and provide additional molecular level details that could impact transport phenomena.

Pulse Shaped Dynamic Nuclear Polarization Under Magic Angle Spinning

2019 ◽  
Author(s):  
ASIF EQUBAL ◽  
Kan Tagami ◽  
Songi Han
Keyword(s):  
Electron Spin ◽  
Lattice Relaxation ◽  
Magic Angle Spinning ◽  
Spin Lattice Relaxation ◽  
Magic Angle ◽  
Total Electron ◽  
Spin Lattice ◽  
Maximum Benefit ◽  
Selective Saturation ◽  
Angle Spinning

In this paper, we report on an entirely novel way of improving the MAS-DNP efficiency by shaped μw pulse train irradiation for fast and broad-banded (FAB) saturation of the electron spin resonance. FAB-DNP achieved with Arbitrary Wave Generated shaped μw pulse trains facilitates effective and selective saturation of a defined fraction of the total electron spins, and provides superior control over the DNP efficiency under MAS. Experimental and quantum-mechanics based numerically simulated results together demonstrate that FAB-DNP significantly outperforms CW-DNP when the EPR-line of PAs is broadened by conformational distribution and exchange coupling. We demonstrate that the maximum benefit of FAB DNP is achieved when the electron spin-lattice relaxation is fast relative to the MAS frequency, i.e. at higher temperatures and/or when employing metals as PAs. Calculations predict that under short T<sub>1e </sub>conditions AWG-DNP can achieve as much as ~4-fold greater enhancement compared to CW-DNP.

An NMR thermometer for cryogenic magic-angle spinning NMR: The spin-lattice relaxation of 127I in cesium iodide

2011 ◽  
Vol 212 (2) ◽  
pp. 460-463 ◽  
Author(s):  
Riddhiman Sarkar ◽  
Maria Concistrè ◽  
Ole G. Johannessen ◽  
Peter Beckett ◽  
Mark Denning ◽  
...  
Keyword(s):  
Lattice Relaxation ◽  
Magic Angle Spinning ◽  
Cesium Iodide ◽  
Spin Lattice Relaxation ◽  
Magic Angle ◽  
Spin Lattice ◽  
Angle Spinning
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