Ionic Motion and Structure of Ion Conductive Glasses

1993 ◽  
Vol 321 ◽  
Author(s):  
T. Akai ◽  
M. Yamashita ◽  
H. Yamanaka ◽  
H. Wakabayashi
Keyword(s):  
Activation Energy ◽  
Relaxation Time ◽  
Slow Motion ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Local Motion ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice ◽  
Two Samples

ABSTRACTThe dynamic structure of xLi2S-Ga2S3-6GeS2 (x=4 and 6) glasses has been investigated by 7Li nuclear magnetic resonance. In two samples similar values of spin-lattice relaxation time (T1) were obtained. The relaxation mechanism at 20MHz and 78MHz is therefore attributed to the local motion of lithium ions. In the glass corresponding to x=6, which shows higher conductivity, the slow motion of ions showing an activation energy of 24.3kJ/Mol has been detected by the spin-lattice relaxation time in the rotating frame (T1p). This value is comparable to the activation energy determined by the conductivity. The existence of this mode is supported by the motional narrowing of the line width which is sensitive to the motion less than 10kHz.

EVALUATION OF THE ACTIVATION ENERGY OF LOCAL DYNAMICS IN SOME POLYISOPRENE-C7D8 SOLUTIONS

2003 ◽  
Vol 17 (27) ◽  
pp. 4935-4944
Author(s):  
M. TODICA ◽  
I. SUCIU
Keyword(s):  
Experimental Data ◽  
Activation Energy ◽  
Relaxation Time ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Spin Lattice Relaxation ◽  
Local Dynamics ◽  
Spin Lattice Relaxation Time ◽  
Spin Lattice ◽  
Nmr Method

The activation energy of the local dynamics of the polymeric segments is calculated from the spin–lattice relaxation time, measured by NMR method. A new algorithm of analysis of the experimental data is proposed in order to increase the accuracy of the evaluation of this parameter. This method was applied for some polyisoprene- C 7 D 8 solutions and for the molten polyisoprene.

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.

Sign in / Sign up

Export Citation Format

Share Document