Temperature-dependent 11B spin-lattice relaxation time for BF4 and CF3BF3 anions in room-temperature ionic liquids

2010 ◽  
Vol 49 (1) ◽  
pp. 6-8 ◽  
Author(s):  
Kikuko Hayamizu ◽  
Seiji Tsuzuki ◽  
Shiro Seki
Keyword(s):  
Ionic Liquids ◽  
Relaxation Time ◽  
Room Temperature ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Room Temperature Ionic Liquids ◽  
Temperature Dependent ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice

scholarly journals Unusual Temperature Dependence of 35Cl NQR Spin-Lattice Relaxation Time in [(CH3)4N]2[MCl6] (M = Pb, Sn, Te)

1991 ◽  
Vol 46 (9) ◽  
pp. 809-814
Author(s):  
Yoshihiro Furukawa ◽  
Yoshihisa Baba ◽  
Shin-ei Gima ◽  
Makoto Kaga ◽  
Tetsuo Asaji ◽  
...  
Keyword(s):  
Relaxation Time ◽  
Temperature Dependence ◽  
Room Temperature ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Unit Cell ◽  
Spin Lattice Relaxation ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice ◽  
Temperature Dependences

Abstract The temperature dependence of the spin-lattice relaxation time (T1H) of 1H NMR measured in tetramethylammonium hexachloroplumbate(IV), (Me4N)2[PbCl6], showed a deep and a shallow minimum near 190 and 115 K, respectively. Since the presence of two kinds of crystallographically nonequivalent cations in the room-temperature Fd 3c unit cell has been reported, the deep T1H minimum was assigned to the overall reorientation of three quarters of the Me4N+ ions and the shallow minimum to that of the remaining cations. Two different temperature dependences of the chlorine NQR spin-lattice relaxation time (T1Q), attributable to a modulated electric-field-gradient by the protonic motion, were observed in (Me4N)2[MCl6] (M = Pb, Sn, Te). One is found in the Pb complex whose T1Q stems from the cationic motion responsible for the deep T1H minimum, and the other one is determined by the cationic motion giving the shallow T1H minimum. Although all room-temperature phases of these complexes are well described by the Fd 3c unit cell, the presence of different temperature dependences of T1Q suggests that the CH3 groups in the respective complexes take different orientations in the crystals

Relative importance of the T-5 and T-7 terms in spin-lattice relaxation time

1979 ◽  
Vol 40 (12) ◽  
pp. 1179-1184 ◽  
Author(s):  
C. Blanchard ◽  
B. Gaillard ◽  
A. Deville
Keyword(s):  
Relaxation Time ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Relative Importance ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice

NUCLEAR SPIN-LATTICE RELAXATION TIME IN TIN

1978 ◽  
Vol 39 (C6) ◽  
pp. C6-1215-C6-1216
Author(s):  
H. Ahola ◽  
G.J. Ehnholm ◽  
S.T. Islander ◽  
B. Rantala
Keyword(s):  
Relaxation Time ◽  
Nuclear Spin ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice ◽  
Nuclear Spin Lattice Relaxation

Pressure dependence of iodine nuclear relaxation in rubidium iodide

1978 ◽  
Vol 56 (10) ◽  
pp. 1386-1389
Author(s):  
Marie D'Iorio ◽  
Robin L. Armstrong
Keyword(s):  
Relaxation Time ◽  
Lattice Relaxation ◽  
Low Pressure ◽  
Lattice Relaxation Time ◽  
Lattice Defects ◽  
Spin Lattice Relaxation ◽  
Polymorphic Phase Transition ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice ◽  
Pressure Phase

The pressure-induced polymorphic phase transition at about 4 k bar in rubidium iodide was studied using nuclear magnetic resonance. The signature of the structural transition is a loss of echo intensity which presumably is due to an increase in the number of lattice defects as a result of the transition. The ratio of the spin–spin relaxation times of the iodine nuclei in the two phases is in agreement with the ratio predicted by a second moment calculation. The actual experimental values, however, are considerably smaller than the theoretical predictions signifying the migration of lattice defects. Estimates of the iodine spin–lattice relaxation time at atmospheric pressure indicate the necessity to include both an anharmonic Raman contribution and a covalency factor. The change in spin–lattice relaxation time with pressure as measured in the low pressure phase is dominated by the change in the lattice parameter. At the critical pressure the spin–lattice relaxation time decreases by a fractional amount which is approximately equal to the fractional volume change characterizing the transition. The pressure derivative of the spin–lattice relaxation time in the high pressure phase is nearly equal to that in the low pressure phase.

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