丝光沸石结构与动力学的钠和铝核磁共振研究
Na and Al NMR Study of Structure and Dynamics in Mordenite.
作者信息
Sergeev N A, Paczwa M, Olszewski M, Panich A M
机构信息
Institute of Physics, University of Szczecin, 70-451 Szczecin, Poland.
Department of Physics, Ben-Gurion University of the Negev, P. O. Box 653, 8410501 Be'er Sheva, Israel.
出版信息
Appl Magn Reson. 2017;48(2):115-124. doi: 10.1007/s00723-016-0847-8. Epub 2016 Nov 9.
Temperature dependencies of Al and Na 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 Na and Al 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 the Na and Al nuclei.
研究了丝光沸石中铝和钠核磁共振谱及自旋晶格弛豫的温度依赖性，实验在静态和魔角旋转条件下进行。我们的数据表明，钠和铝原子核的自旋晶格弛豫主要由核四极矩与晶体电场梯度的相互作用决定，该相互作用由水分子在丝光沸石通道中的平移运动调制。在低于200K的温度下，核自旋与顺磁杂质的偶极相互作用成为钠和铝原子核的重要弛豫机制。
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