The magnetic field and temperature dependences of proton spin-lattice relaxation in proteins

2007 ◽  
Vol 126 (17) ◽  
pp. 175105 ◽  
Author(s):  
Yanina Goddard ◽  
Jean-Pierre Korb ◽  
Robert G. Bryant
Keyword(s):  
Magnetic Field ◽  
Lattice Relaxation ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Temperature Dependences ◽  
The Magnetic Field

A proton FFT study of the aromatic and alkyl motions in the liquid crystal CBOOA: Orientational order fluctuations in the isotropic phase

1976 ◽  
Vol 54 (22) ◽  
pp. 2282-2286 ◽  
Author(s):  
J. J. Visintainer ◽  
E. Bock ◽  
Ronald Y. Dong ◽  
E. Tomchuk
Keyword(s):  
Liquid Crystal ◽  
Critical Temperature ◽  
Orientational Order ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Proton Spin ◽  
Spin Lattice Relaxation ◽  
Isotropic Phase ◽  
Spin Lattice ◽  
Temperature Dependences

Proton line shapes and spin–lattice relaxation were studied in the isotropic phase of the liquid crystal n-p-cyanobenzylidene-p-n-octyloxyaniline (CBOOA) using Fast Fourier Transform (FFT) spectroscopy. The proton spin–lattice relaxation time T1 above the nematic–isotropic phase transition was measured, at several Larmor frequencies, for the resolved peaks in the FFT spectra. The critical temperature dependences of (T1)cf, the T1, due to collective order fluctuations, are thus studied for the aromatic and the alkyl proton groups. The critical temperature behavior of CBOOA is compared with the predictions of the model based on short-range nematic orientational order fluctuations.

PSEUDOGAP AND SUPERCONDUCTIVITY UNDER HIGH MAGNETIC FIELD IN UNDERDOPED HIGH-Tc CUPRATE

1999 ◽  
Vol 13 (29n31) ◽  
pp. 3764-3766 ◽  
Author(s):  
G.-Q. ZHENG ◽  
Y. KITAOKA ◽  
K. ASAYAMA ◽  
Y. KODAMA ◽  
W. G. CLARK ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Correlation Effects ◽  
Strong Electron ◽  
High Tc ◽  
Spin Lattice ◽  
Nuclear Spin Lattice Relaxation ◽  
Electron Correlation Effects ◽  
The Magnetic Field

The responses to the magnetic field (H) of the superconductivity and the pseudogap in the underdoped high- T c cuprate YBa 2 Cu 4 O 8(Tc=74 K) are reported up to 23.2 T based on NMR measurements. Even though H=23.2 T reduces Tc by 19 K, no effect is seen on the normal-state pseudogap, which continues in the temperature region where the superconductivity is destroyed by the field. This suggests that the pseudogap is a consequence of strong electron correlation effects. For temperatures T≤15 K, the H- and T-variation of the 63 Cu nuclear spin-lattice relaxation rate (1/T1) is 1/T1∝TH and also the Knight shift increases with increasing H. We interpret our results as evidence for H-induced quasiparticle states that extend from the d-wave vortex centers with an ungapped spectrum.

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