119Sn-mössbauer, IR, and DSC study of tin oxyfluoride glasses

Effect of OH-content on thermal and chemical properties of SnOP2O5 glasses

“…Two sites could be assumed by fitting procedures, one with r $ 3.1 mm/s and D $ 1.8 mm/s and another with r $ 3.5 mm/s and D $ 1.6 mm/s. Similar values were reported by Nishida et al [7]. It could be assumed that the Sn 2+ ions have a similar environment as in Sn 2 P 2 O 7 , which has r = 3.42 mm/s and D = 1.61 mm/s, or in Sn 3 (PO 4 ) 2 , with r = 3.12 mm/s and D = 1.90 mm/s.…”

“…It could be assumed that the Sn 2+ ions have a similar environment as in Sn 2 P 2 O 7 , which has r = 3.42 mm/s and D = 1.61 mm/s, or in Sn 3 (PO 4 ) 2 , with r = 3.12 mm/s and D = 1.90 mm/s. They [7] found a systematic increase of T g , due to the substitution of SnO for SnF 2 , reflecting increased intermolecular and intramolecular force constants. Since the Mö ssbauer parameters are almost constant in the xSnOA(70Àx)SnF 2 A30P 2 O 5 glasses, they concluded from the drastic increase in T g that Sn 2+ and Sn 4+ are not constituents of the covalent network structure but are loosely and ionically bonded at interstitial sites.…”

“…However, low melting glasses usually exhibit poor chemical stabilities and their hygroscopic nature makes them unsuitable for many commercial applications. Previous studies [1][2][3][4][5][6][7][8][9][10] of stannous fluorophosphate glasses in the binary system SnF 2 AP 2 O 5 and in the ternary systems SnF 2 APbF 2 AP 2 O 5 and SnOASnF 2 AP 2 O 5 had shown that the properties of these glasses are extremely sensitive to variations in melting history. Usually, the glasses were prepared at low temperature, around 400-500°C, and for short times, 15 min to 1 h. Volatilization losses during melting can change the composition, with accompanying changes in properties.…”

Unique thermal conductivity, Young’s modulus and local structure of 72SnO–28P₂O₅ glass

“…29) For the Mössbauer spectrum shown in Fig. 3 Table 2, i.e., ¤ = +3.34 mm/s, is very close to the value of ¤ = +3.30 mm/s reported by Nishida et al 30) The presence of two sites with large quadrupole splitting values of ¦ = 1.77 and 1.31 mm/s (Table 2), i.e., the site-II and site-III, indicates that Sn 2+ ions in 72SnPO glass prepared in this study have mainly two different coordination states with large site distortions (electric field gradients). As seen in Fig.…”