title: Proton Dipolar Spin-Lattice Relaxation in Nano-channels of Natrolite.
abstract: The1H nuclear magnetic resonance (NMR) spectra and the dipolar spin-lattice relaxation timeT1Dfor1H in the natural natrolite (Na2Al2Si3O10·2H2O) have been measured in the temperature range of 190-390 K. From the temperature transformations of1H NMR spectra, it follows that atT> 300 K, the diffusion of water molecules along the nano-channels is observed. From experimentalT1Ddata, it follows that the 180° flip motion of the water molecules takes place in natrolite. At low temperature (T< 250 K), the dipolar interaction with paramagnetic impurities as a relaxation mechanism of1H nuclei becomes significant.
authors.affiliation: Department of Mathematical and Physics, Institute of Physics, University of Szczecin, Wielkopolska str.-15, 70-451 Szczecin, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Paczwa
authors.affiliation: V.I.Vernadsky Crimean Federal University, 295007 Simferopol, Crimea.
authors.forename: A A
authors.initials: AA
authors.lastname: Sapiga
authors.affiliation: Department of Mathematical and Physics, Institute of Physics, University of Szczecin, Wielkopolska str.-15, 70-451 Szczecin, Poland.
authors.forename: M
authors.initials: M
authors.lastname: Olszewski
authors.affiliation: Department of Mathematical and Physics, Institute of Physics, University of Szczecin, Wielkopolska str.-15, 70-451 Szczecin, Poland.
authors.forename: N A
authors.initials: NA
authors.lastname: Sergeev
authors.affiliation: V.I.Vernadsky Crimean Federal University, 295007 Simferopol, Crimea.
authors.forename: A V
authors.initials: AV
authors.lastname: Sapiga