Effect of minor additions on structure and volatilization loss in simulated nuclear borosilicate glasses

Structure of borosilicate glasses and melts: A revision of the Yun, Bray and Dell model

“…3(b) and (c)). This assumption is in agreement with the results of Parkinson et al [15], who showed that danburite tends to decompose at high temperature, increasing the volatility of borosilicate glasses with high danburite content. More details about this Raman study are reported elsewhere [27].…”

“…Pyrex @ , or optical glasses and also for storage of nuclear waste. A considerable amount of results have been obtained about the structure of these glasses [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19], mainly via NMR analyses of 11 B, 17 O, 23 Na and 29 Si, Raman spectroscopy and neutron diffraction [18]. A comprehensive model was proposed almost 30 years ago in the present journal by Yun and Bray, Yun et al [1,2] and by Dell et al [3], based on experimental 11 O 3 ] (where [Á] mol%) are the most important composition-related structural parameters.…”

“…Although this model is still a valuable starting reference for the structure evolution as alkali cations are added to the glass system, several authors have criticized it. In particular, some recent publications [4][5][6][7][8][15][16][17][18][19], have shown that in general alkali cations are more randomly mixed to the borate and silica networks than was assumed in [1][2][3]. At a quantum level, it is not always true that exactly one Na + is needed to compensate the charge of one BO À 4 unit [13], so it is not fully correct to assume the value R = 0.5 as a starting point for the formation of borosilicate units.…”

“…1(b)). Danburite is a mineral of composition CaOÁB 2 O 3 Á2SiO 2 [4,[15][16][17]21], and danburite-like rings include two SiO 4 and two BO 4 tetrahedra ( Fig. 2(a)).…”

Quantitative measurement of Q3 species in silicate and borosilicate glasses using Raman spectroscopy

“…Relatively small additions of aluminum, lanthanum and magnesium oxides to the CsMW system alter the Q 3 fraction significantly for compositions of identical caesium oxide content, with Al 2 O 3 and La 2 O 3 effectively behaving as network intermediates, whilst MgO behaves as a modifier. This behavior is discussed in more detail in [24]. In Fig.…”