A neutron diffraction study of six M2O.M´2O.5B2O3 mixed-modifier di-pentaborate glasses

Mössbauer and differential thermal analysis studies of iron alkali lead-phosphate glasses

“…The detection of iron ions in sixfold coordination is common in different types of glasses [32]. Moreover, the existence of Fe 2+ in fivefold and sixfold coordination was confirmed previously by a neutron diffraction study [30]. On the other hand, the existence of both Fe 2+ and Fe 3+ in fivefold coordination (bipyramidal coordination) are observed in phosphate glass and some iron minerals [24,[44][45][46][47][48][49][50].…”

“…IS reflects the amount of charge density at probe nucleus, which depends on the degree of localization or delocalization of charges. So, it provides valuable information about the total charge at a given site in addition to the different properties of chemical bonds [29,30]. According to the 57 Fe Mössbauer measurements for oxide glasses; the higher values of IS indicating five or six coordination of the iron atoms while, the higher values of QS indicating low coordination symmetries of the iron atoms like tetrahedron sites [30].…”

“…So, it provides valuable information about the total charge at a given site in addition to the different properties of chemical bonds [29,30]. According to the 57 Fe Mössbauer measurements for oxide glasses; the higher values of IS indicating five or six coordination of the iron atoms while, the higher values of QS indicating low coordination symmetries of the iron atoms like tetrahedron sites [30]. According to several authors [31,32] and due to the recent interest in the use of iron phosphate glass in encapsulating radioactive waste for long-term storage, they performed computer simulations using molecular dynamics to study the structure of different compositions of iron phosphate-based glasses.…”

Deciphering the structure and potassium-ion transport mechanism of potassium borate glass

“…15-19 11 B NMR experimental results and physical-chemical models suggest that the peak value of N 4 occurs at x = 0.30. 19,20 Wright et al 21 − /NBO ratios, alkali and alkaline earth metal cations primarily act as "network formers", while at higher NBO contents, they primarily act as "network modifiers". [23][24][25][26] Furthermore, at higher NBO contents, the main oxygen atoms in B∅ 4 − units are also NBOs.…”