Sodium aluminophosphate glass

Network former connectivities have been explored in a variety of phosphate glasses containing aluminum or boron as a second network former component. A number of studies have been published on the sodium aluminophosphate glass system [82-85]. The Al NMR spectra of these glasses show three distinct resonances, attributable to AIO4, AIO5, and A106 units. All of these environments are intimately connected to phosphorus species, as revealed by 2D CPMAS het-eronuclear correlation and REDOR experiments [83]. 

Solid-state FK and P / Na TRAPDOR NMR experiments have been used to investigate the spatial distribution of aluminium and sodium cations with respect to the phosphate backbone for a series of sodium aluminophosphate glasses, jcAl(2)0(4).50Na(2)0.(50—x)P205 (0 < x < 17.5). ... 

Figure 6.6 F 1s spectra from a sodium aluminophosphate glass containing (a) 5 wt % F and (6) 15 wt % F. (From Reference 22.)...

P— P correlations in aluminophosphates, and Si— oi correlations in sodium borosihcate glass and silicate-1. Interestingly, they demonstrated covariance processing in double-quantum correlation experiments employing POST-C7 [71], BABA [72], and INADEQUATE [73]. In double-quantum 2D spectroscopy, time evolution along the indirect dimension is characterized by the frequencies given by the sum of the chemical shifts between the correlated spins so that horizontal pairs of correlation peaks appear as shown in Fig. 3. There, 125 data sets were acquired with a step of 12.5 ps. Thus, the coherence profile during the evolution time was truncated at 1.6 ms. 

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