NMR Study of Synthetic Gallosilicate Natrolite

Abstract

Solid-state 29Si and 71Ga NMR was used to study the synthetic gallosilicate Na16Ga16Si24O80 ·16H2O (Ga–natrolite). It has been shown that Ga–natrolite contains mainly Si(GaO4)3(SiO4) and Si(GaO4)2(SiO4)2-structural units and has sufficiently ordered structure. Temperature dependence of the spin–lattice relaxation time T1 of 71Ga nuclei has also been studied using solid-state NMR. Spin–lattice relaxation of the 71Ga was determined to be governed by the electric quadrupole interaction with the crystal electric field gradients modulated by translational motion of H2O molecules in the Ga–natrolite pores.

Network Formation in Borosilicate Glasses with Aluminum or Gallium: Implications for Nepheline Crystallization

“…As a further test of this competition among network formers, we have conducted analogous experiments with gallium, instead of aluminum, incorporation. Due to the similarities in the chemical properties of group-13 cations, Al 3+ and Ga 3+ , it is not surprising that they have been shown to play similar structural roles in oxide glasses. − For example, the chemical environments of gallium in binary gallate , and phosphogallate glasses , and in gallosilicate crystalline systems − are well known, and the speciation of gallium in silicate glasses and its effect on the Si speciation have been investigated by molecular dynamics simulations and nuclear magnetic resonance (NMR) . Gallium has two NMR-active isotopes ( 69 Ga and 71 Ga) with substantial quadrupole moments, which can lead to a significant quadrupolar broadening of the NMR signals .…”