Temperature dependencies of 27Al and 23Na 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 the 23Na and 27Al nuclei are mainly governed by interaction of nuclear quadrupole moments with electric field gradients of the… (More)
The 1 H nuclear magnetic resonance (NMR) spectra and the dipolar spin– lattice relaxation time T 1D for 1 H in the natural natrolite (Na 2 Al 2 Si 3 O 10 Á2H 2 O) have been measured in the temperature range of 190–390 K. From the temperature transformations of 1 H NMR spectra, it follows that at T [ 300 K, the diffusion of water molecules along the… (More)
The quadrupolar and dipolar interactions of spins during the radio frequency (RF) pulses are considered. It is shown that due to these interactions the two-pulse echo signal is observed at the shifted time t(e) = tau + t1/2 (t1 = width of the first RF pulse, tau = time interval between the pulses).
The shape of the free induction decay for the case in which the amplitude B1 (B1 = omega 1/gamma) of the RF pulse is comparable with local magnetic fields at sites of the nuclei is considered. It is shown that the shape of the FID G(t + tau) (where tau is the width of a RF pulse, t is the time after a RF pulse) depends on the shape of the FID G0(t)… (More)