Dominance of the spin-dipolar NMR relaxation mechanism in fullerene superconductors

1993 ◽  
Vol 47 (18) ◽  
pp. 12373-12376 ◽  
Author(s):  
V. P. Antropov ◽  
I. I. Mazin ◽  
O. K. Andersen ◽  
A. I. Liechtenstein ◽  
O. Jepsen
Keyword(s):  
Nmr Relaxation ◽  
Relaxation Mechanism

scholarly journals Elucidating the 1H NMR Relaxation Mechanism in Polydisperse Polymers and Bitumen Using Measurements, MD Simulations, and Models

2020 ◽  
Vol 124 (20) ◽  
pp. 4222-4233 ◽  
Author(s):  
Philip M. Singer ◽  
Arjun Valiya Parambathu ◽  
Xinglin Wang ◽  
Dilip Asthagiri ◽  
Walter G. Chapman ◽  
...  
Keyword(s):  
1H Nmr ◽  
Nmr Relaxation ◽  
Md Simulations ◽  
Relaxation Mechanism

1HNMR Study on the Motion of NH4+ in Ferroelectric NH4H(ClH2CCOO)2 and Mixed (NH4)1-xRbxH(ClH2CCOO)2 (x = 0.15)

2002 ◽  
Vol 57 (11) ◽  
pp. 883-887 ◽  
Author(s):  
M. Zdanowska-Fra̡czek ◽  
A. Kozaka ◽  
R. Jakubasb ◽  
J. Wa̡sickia ◽  
R. Utrechta
Keyword(s):  
Relaxation Time ◽  
Group Dynamics ◽  
Nmr Relaxation ◽  
Activation Parameters ◽  
Lattice Relaxation ◽  
Relaxation Mechanism ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Temperature Dependent ◽  
Spin Lattice

Temperature-dependent proton NMR relaxation time measurements have been performed at 60 MHz in order to study the NH4+ dynamics in ferroelectric NH4H(ClH2CCOO)2 and mixed Rbx(NH4)1-x(ClH2CCOO)2, where x = 0.15. The data indicate that the dominant relaxation mechanism for the NMR spin-lattice relaxation time T 1 in both crystals involves simultaneous NH4 group reorientation about their C2 and C3 symmetry axis in the paraelectric phase. Details of the NH4+reorientation have been inferred from analysis of temperature dependence of T1 assuming the Watton model. The activation parameters of the motionshave been determined.It has been found that the substitution of Rb does not change the activation parameters of the NH4 group dynamics.

scholarly journals Correction to “Elucidating the 1H NMR Relaxation Mechanism in Polydisperse Polymers and Bitumen Using Measurements, MD Simulations, and Models”

2021 ◽  
Vol 125 (40) ◽  
pp. 11338-11339
Author(s):  
Philip M. Singer ◽  
Arjun Valiya Parambathu ◽  
Xinglin Wang ◽  
Dilip Asthagiri ◽  
Walter G. Chapman ◽  
...  
Keyword(s):  
1H Nmr ◽  
Nmr Relaxation ◽  
Md Simulations ◽  
Relaxation Mechanism

A laboratory study of the effect of Fe(II)-bearing minerals on nuclear magnetic resonance (NMR) relaxation measurements

Geophysics ◽  
2010 ◽  
Vol 75 (3) ◽  
pp. F71-F82 ◽  
Author(s):  
Kristina Keating ◽  
Rosemary Knight
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Relaxation Rate ◽  
Nmr Relaxation ◽  
Relaxation Mechanism ◽  
Surface Relaxation ◽  
Fast Diffusion ◽  
Relaxation Rates ◽  
Bulk Fluid ◽  
Surface Relaxivity ◽  
Diffusion Relaxation

A laboratory study was conducted to measure the effect of the mineralogic form and concentration of iron(II) [Fe(II)] minerals on nuclear magnetic resonance (NMR) relaxation rates of water-saturated sand mixtures. We measured mixtures of quartz sand and three common Fe(II)-bearing minerals in granular form: siderite [Formula: see text], pyrite [Formula: see text], and pyrrhotite ([Formula: see text]; [Formula: see text]) at two concentrations of iron by weight. The NMR response of these samples was used to calculate four transverse relaxation rates for each Fe(II) mineral mixture: total mean log, bulk fluid, diffusion, and surface relaxation rates. The surface area of the samples was used to calculate the surface relaxivity of the sample and the magnetically active surface. For each iron mineral, the mean log and surface relaxation rates were greater for samples with higher Fe(II) concentration. For the siderite,pyrrhotite, and high-concentration pyrite mixtures, surface relaxation was the dominant relaxation mechanism. Bulk fluid relaxation contributed significantly to the total relaxation for the siderite and pyrite mixtures; for the low-concentration pyrite mixtures, bulk fluid relaxation was the dominant relaxation mechanism. For the pyrrhotite mixtures, the diffusion relaxation rate was nonzero and slower than the surface relaxation rate; for the siderite and pyrite mixtures, the diffusion relaxation rate was zero. Surface relaxivity calculations revealed that, for the pyrite mixtures, relaxation occurred in the fast diffusion regime; for the siderite and pyrrhotite mixtures, relaxation did not occur in the fast diffusion regime. The range of surface relaxivity values calculated depends on mineralogic form. We conclude that Fe(II) concentration and mineralogic form are important factors in determining relaxation rate.

Influence Of Proton Exchange On NMR Relaxation Mechanism Of 7Li

2015 ◽  
Vol 60 (5) ◽  
pp. 401-405
Author(s):  
A.I. Ovcharenko ◽  
◽  
E.D. Chesnokov ◽  
I.G. Vertegel ◽  
L.S. Ivanova ◽  
...  
Keyword(s):  
Nmr Relaxation ◽  
Relaxation Mechanism ◽  
Proton Exchange

Mononucleotides 31P NMR relaxation measurement

1983 ◽  
Vol 80 ◽  
pp. 831-832 ◽  
Author(s):  
A.M. Avedikian ◽  
D. Besserre ◽  
M. Delepierre
Keyword(s):  
31P Nmr ◽  
Nmr Relaxation ◽  
Relaxation Measurement
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