Molecular Dynamics in Tetramethyl Ammonium Hexabromo Selenate [N(CH3)4]2SeBr6. A Proton NMR Study
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چکیده
spin-lattice relaxation time Ti and second moment M 2 have been studied as a function of temperature over the temperature range 445 to 77 K. A discontinuous change in Ti at 365 K, indicates the presence of a phase transition, while the slope change at 152 K, is attributed to a change in the TMA ion dynamics from tumbling to torsion. The 7i results could be explained in terms of inequivalent TMA ions and their small angle torsional oscillations. A second moment (M2) transition occurs around 160 K and is ascribed to the freezing of TMA tumbling and C H 3 reorientation.
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