scholarly journals Internal Dynamics of Ionic Liquids over a Broad Temperature Range—The Role of the Cation Structure

Materials ◽  
2021 ◽  
Vol 15 (1) ◽  
pp. 216
Author(s):  
Danuta Kruk ◽  
Mariusz Jancelewicz ◽  
Adam Klimaszyk ◽  
Roksana Markiewicz ◽  
Zbigniew Fojud ◽  
...  
Keyword(s):  
Ionic Liquids ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Arrhenius Law ◽  
Dynamical Processes ◽  
Temperature Range ◽  
Spin Lattice ◽  
Relaxation Experiments ◽  
Chain Lengths

1H and 19F spin-lattice relaxation experiments have been performed for a series of ionic liquids sharing the same anion: bis(trifluoromethanesulfonyl)imide but including cations of different alkyl chain lengths: butyltriethylammonium, triethyloctylammonium, dodecyltriethylammo-nium and hexadecyltriethylammonium. The studies have been carried out in the temperature range from 383 to 108 K at the resonance frequency of 200 MHz (for 1H). A quantitative analysis of the relaxation data has revealed two dynamical processes for both kinds of ions. The dynamics have been successfully modeled in terms of the Arrhenius law. The timescales of the dynamical processes and their temperature evolution have been discussed in detail, depending on the structure of the cation.

NQR Relaxation Studies on Halogenomethyl Groups in Halogenoacetates

1998 ◽  
Vol 53 (6-7) ◽  
pp. 480-483 ◽  
Author(s):  
Maria Zdanowska-Fnjczek
Keyword(s):  
Room Temperature ◽  
Relaxation Times ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Effect Of Temperature ◽  
Relaxation Theory ◽  
Temperature Range ◽  
Spin Lattice ◽  
Relaxation Studies

Abstract The effect of temperature on the chlorine NQR spin-lattice relaxation times in CsH(ClH2-CCOO)2 , KH(Cl3 CCOO) 2 and N(CH3)4 H(ClF2CCOO)2 has been studied in the temperature range 77 K to room temperature. The results were discussed on the basis of NQR relaxation theory.

scholarly journals The role of the glassy dynamics and thermal mixing in the dynamic nuclear polarization and relaxation mechanisms of pyruvic acid

2014 ◽  
Vol 16 (48) ◽  
pp. 27025-27036 ◽  
Author(s):  
M. Filibian ◽  
S. Colombo Serra ◽  
M. Moscardini ◽  
A. Rosso ◽  
F. Tedoldi ◽  
...  
Keyword(s):  
Relaxation Rate ◽  
Dynamic Nuclear Polarization ◽  
Pyruvic Acid ◽  
Nuclear Polarization ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Relaxation Rates ◽  
Thermal Mixing ◽  
Spin Lattice

In pyruvic acid containing 15 mM trityl below 4 K 13C polarization and spin–lattice relaxation rates are proportional to the spin–lattice relaxation rate of electrons, suggesting an efficient thermal mixing scenario.

The influence of thermal conduction in spin-lattice relaxation experiments

Physica B+C ◽  
1978 ◽  
Vol 95 (2) ◽  
pp. 173-182 ◽  
Author(s):  
G.J. Gerritsma ◽  
J. Flokstra ◽  
G.A. Hartemink ◽  
J.J.M. Scholten ◽  
A.J.W.A. Vermeulen ◽  
...  
Keyword(s):  
Thermal Conduction ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Relaxation Experiments

The role of the ordinary and anharmonic Raman processes in Rb2PtI6

1978 ◽  
Vol 56 (11) ◽  
pp. 1461-1467 ◽  
Author(s):  
Robert G. C. McElroy ◽  
Robin L. Armstrong
Keyword(s):  
Nuclear Spin ◽  
Lattice Relaxation ◽  
Experimental Results ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
Raman Process ◽  
Nuclear Spin Lattice Relaxation ◽  
Rare Opportunity

Measurements of iodine nuclear spin lattice relaxation in Rb2PtI6 provide a rare opportunity to directly measure the separate contributions of the ordinary and anharmonic Raman processes. It is shown that for this crystal one may separately determine W1 and W2 and that these rates may be uniquely related to the two Raman processes. The experimental results show that the anharmonic Raman process is dominant but not to the total exclusion of the ordinary Raman process.

scholarly journals The Orbit?Lattice Interaction for Lanthanide Ions. II. Strain and Relaxation Time Predictions for Cubic Systems

1980 ◽  
Vol 33 (4) ◽  
pp. 733 ◽  
Author(s):  
DJ Newman
Keyword(s):  
Crystal Field ◽  
Lattice Relaxation ◽  
Lanthanide Ions ◽  
Spin Lattice Relaxation ◽  
Superposition Model ◽  
Unknown Parameters ◽  
Paramagnetic Resonance ◽  
Spin Lattice ◽  
Relaxation Experiments ◽  
Cubic Systems

An analysis of dynamic crystal field data for cubic systems is carried out in order to assess the possible usefulness of the superposition model in understanding the results of lattice strain and spin-lattice relaxation experiments. The data used in this work are the electron paramagnetic resonance (EPR) results for strained cubic crystals obtained by Buisson, Baker and their coworkers, and the spinlattice relaxation results obtained by Buisson, Stapleton and their coworkers. A method of generalizing the superposition model to take into account long range electrostatic contributions without introducing additional unknown parameters is proposed, and shown to give consistent results. It is concluded that differences between bulk and local strains must be taken into account in any model of the dynamic crystal field, if it is to achieve success.

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