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MAS-NMR studies of carbonate retention in a very wide range of Na2O-SiO2 glasses

“…In particular, we see evidence from both carbon and sodium MAS-NMR for glassy carbonate in at least two structural roles in the highest Na 2 O-content glasses. Second, in glass science 4,[8][9][10][11][12][13][14] as our results extend the established range of the Na 2 O-SiO 2 glass-forming system and show structural and compositional evolution as a result of carbonate incorporation. Third, in glass technology 24 as our results show that stable carbonate-rich glasses can be produced at the extreme ends of the simple glass-forming systems on which many technological glasses are based that retain only parts-per-million levels of CO 2 (e.g.…”

“…This investigation covers two sets of samples, one made with natural abundance Na 2 CO 3 and one with 99% 13 C enriched Na 2 CO 3 . The 13 C-enriched samples were also doped with a 0.1 wt% iron oxide (Fe 2 O 3 ) to decrease the NMR relaxation time without affecting the peak widths or shifts 8 . Both sets of samples were synthesised under comparable conditions, and the melting process was identical for the corresponding samples from each set.…”

Role of manganese on the structure, crystallization and sintering of non-stoichiometric lithium disilicate glasses

“…Mn bonded to oxygen in octahedral coordination might account for the high D o values, while the isolation of the structural units could help explaining the high B values. Upon studying the effects of small additions of Mn into sodium silicate glasses, Mortuza et al 50 arrived to a similar conclusion, suggesting that Mn is not chemically bonded to the glass network.…”

“…Also with increasing manganese content from 0.5 to 2 mol% the overall paramagnetic broadening of the NMR peaks can be noticed due to small additions of paramagnetic ions. 50 In contrast, no change in the chemical shi can be observed in 27 Al MAS-NMR spectra of glasses (Fig. 4b), indicating that network connectivity of Al 2 O 3 polyhedra was unaffected by Mn addition.…”

Oxide glasses with magnetic nanoparticles: transparent magnets (Faraday rotation and electron magnetic resonance studies)

“…Indeed, several authors have noted a significant influence of Mn oxide additions on the structure and properties of glasses. For instance, MnO additions enhance crystallization of sodium silicate glasses [73]. The influence of the Mn content on the character of bonds has been demonstrated for MnO-P 2 O 5 -TeO 2 [74,75] and alkali fluoroborate glasses [76].…”