Structural characterization of noncrystalline solids and glasses using solid state NMR

6Li, 7Li nuclear magnetic resonance investigation of lithium coordination in binary phosphate glasses

“…As pointed out previously the 7Li NMR line width is homogeneously broadened by 7Li-7Li and 7Li-31P dipolar coupling giving rise to rather broad lines that are not easily interpreted. [28,29,45] For the less abundant 'Li nuclei, the line broadening is inhomogenous in nature and reflects changes in the distribution of Li coordination environments. In general the 'Li (Table 2) is significantly lower than that observed in the corresponding lithium phosphate crystals (Table 1).…”

Structure of Ternary Aluminum Metaphosphate Glasses

“…The relative abundance of Q n species in a glass can be quantified by several techniques, with high-resolution 31 P nuclear magnetic resonance (NMR) as the most conspicuous one. 13 Starting from P 2 O 5 glass, containing only Q 3 groups, the addition of a modifier oxide such as Na 2 O creates nonbridging oxygens (NBO) that depolymerize the tetrahedral network, generating Q n groups of decreased PÀOÀP connectivity. 14 In the vast majority of simple phosphate glasses, the distribution of species is close to binary, i.e., at most two types of Q n units are formed at any given composition, with some effects of disproportionation depending on composition and glass processing conditions.…”

Uncovering the Local Magnesium Environment in the Metal–Organic Framework Mg2(dobpdc) Using 25Mg NMR Spectroscopy

“…The data in Figure 4 suggest that a spinning rate of greater than The spin-lattice relaxation of 25 Mg in solids is usually governed by the strong quadrupolar coupling interaction between the nucleus and the local EFG, which can be effectively accelerated if the local EFG is fluctuated by the thermal motions within the MOF. 50 The details of such motions and their consequence to the local disorder at Mg centers will be discussed later. Shortening the recycle delays under MAS, then, edits the spectra to favor the Mg centers with local disorder.…”