87Rb spin-lattice relaxation times in ferroelectric-paraelectric-incommensurate phases of Rb2CoBr4 using static NMR and MAS NMR

2017 ◽  
Vol 1134 ◽  
pp. 381-384 ◽  
Author(s):  
Ae Ran Lim
RSC Advances ◽  
2018 ◽  
Vol 8 (59) ◽  
pp. 34110-34115 ◽  
Author(s):  
Ae Ran Lim ◽  
Yong Lak Joo

To understand the dynamics of the cation in layered perovskite-type (CH3CH2NH3)2CuCl4, the temperature-dependent chemical shifts and spin–lattice relaxation times T1ρ have been measured using 1H MAS NMR and 13C CP/MAS NMR techniques.


1989 ◽  
Vol 149 ◽  
Author(s):  
E. J. Vanderheiden ◽  
G. A. Williams ◽  
P. C. Taylor ◽  
F. Finger ◽  
W. Fuhs

ABSTRACT1H NMR has been employed to study the local environments of bonded hydrogen and trapped molecular hydrogen (H2) in a series of a-Si1−xGex:H alloys. There is a monotonic decrease of bonded hydrogen with increasing x from ≈ 10 at. % at x = 0 (a-Si:H) to ≈ 1 at. % at x = 1 (a-Ge:H). The amplitude of the broad 1H NMR line, which is attributed to clustered bonded hydrogen, decreases continuously across the system. The amplitude of the narrow 1H NMR line, which is attributed to bonded hydrogen essentially randomly distributed in the films, decreases as x increases from 0 to ≈ 0.2. From x = 0.2 to x ≈ 0.6 the amplitude of the narrow 1H NMR line is essentially constant, and for x ≥ 0.6 the amplitude decreases once again. The existence of trapped H2 molecules is inferred indirectly by their influence on the temperature dependence of the spin-lattice relaxation times, T1. Through T1, measurements it is determined that the trapped H2 concentration drops precipitously between x = 0.1 and x = 0.2, but is fairly constant for 0.2 ≤ x ≤ 0.6. For a-Si:H (x = 0) the H2 concentration is ≈ 0.1 at. %, while for x ≥ 0.2 the concentration of H2 is ≤ 0.02 at. %.


1995 ◽  
Vol 99 (12) ◽  
pp. 4148-4154 ◽  
Author(s):  
Eddy Walther Hansen ◽  
Ralf Schmidt ◽  
Michael Stoecker ◽  
Duncan Akporiaye

2004 ◽  
Vol 167 (2) ◽  
pp. 221-227 ◽  
Author(s):  
Ferenc Murányi ◽  
Ferenc Simon ◽  
Ferenc Fülöp ◽  
András Jánossy

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