23Na and27Al NMR Study of Structure and Dynamics in Mordenite.
Temperature dependencies of27Al and23Na nuclear magnetic resonance spectra and spin-lattice relaxations in mordenite have been studied in static and magic angle spinning regimes. Our data show that the spin-lattice relaxations of the23Na and27Al nuclei are mainly governed by interaction of nuclear quadrupole moments with electric field gradients of the crystal, modulated by translational motion of water molecules in the mordenite channels. At temperatures below 200 K, the dipolar interaction of nuclear spins with paramagnetic impurities becomes an important relaxation mechanism of the23Na and27Al nuclei.
Institute of Physics, University of Szczecin, 70-451 Szczecin, Poland.
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Sergeev
Institute of Physics, University of Szczecin, 70-451 Szczecin, Poland.
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Paczwa
Institute of Physics, University of Szczecin, 70-451 Szczecin, Poland.
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Olszewski
Department of Physics, Ben-Gurion University of the Negev, P. O. Box 653, 8410501 Be'er Sheva, Israel.
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Panich