Short-range structure, the role of bismuth and property–structure correlations in bismuth borate glasses

Abstract

Bismuth-containing borate glasses, xBi2O3-(1-x)B2O3, were synthesized in the broad composition range 0.20≤x≤0.80 by melting in Pt crucibles and splat-quenching between two metal blocks. Infrared reflectance spectra, measured in the range...

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“…The replacement of bridging oxygen (Ø) by a nonbridging one (O À ) reduces the symmetry to C 2V from D 3h , while the doubly degenerate (E 0 ) asymmetric stretching mode will split into two IR-active components of A 1 and B 2 symmetry. [46][47][48][49] Fig. 4 (a) Percent crystallinity and amorphous phase fraction determined from the XRD data of S4A7EDxB (0 r x r 60 mol% B 2 O 3 ) samples; (b) phase distribution revealed by Rietveld phase analysis of the diffractograms shown in Fig.…”

“…The replacement of bridging oxygen (Ø) by a non-bridging one (O − ) reduces the symmetry to C 2V from D 3h , while the doubly degenerate ( E ′) asymmetric stretching mode will split into two IR-active components of A 1 and B 2 symmetry. 46–49…”

“…Changes in the number of B–O − and B–Ø bonds undergoing stretching vibrations in BØ 2 O − and BØ 3 units resulted in the red-shift and asymmetry of these bands. 18,49 In particular, the red-shift suggests stronger interactions between the non-bridging oxygens and other cations—Sr 2+ , Al 3+ , Eu 2+ , and Dy 3+ —that consequently result in weaker B–O − bonding. 49…”

“…Changes in the number of B-O À and B-Ø bonds undergoing stretching vibrations in BØ 2 O À and BØ 3 units resulted in the red-shift and asymmetry of these bands. 18,49 In particular, the red-shift suggests stronger interactions between the nonbridging oxygens and other cations-Sr 2+ , Al 3+ , Eu 2+ , and Dy 3+ -that consequently result in weaker B-O À bonding. 49 For the S4A7EDxB compositions of 40 r x r 60 mol% B 2 O 3 , these trends continued in the 1335-1342 cm À1 spectral shift range, which was attributed to the progressive depolymerization in the borate network in superstructural units transforming into metaborate (BØ 2 O) À and then into orthoborate (BO 3 ) 3À monomers.…”

“…18,49 In particular, the red-shift suggests stronger interactions between the nonbridging oxygens and other cations-Sr 2+ , Al 3+ , Eu 2+ , and Dy 3+ -that consequently result in weaker B-O À bonding. 49 For the S4A7EDxB compositions of 40 r x r 60 mol% B 2 O 3 , these trends continued in the 1335-1342 cm À1 spectral shift range, which was attributed to the progressive depolymerization in the borate network in superstructural units transforming into metaborate (BØ 2 O) À and then into orthoborate (BO 3 ) 3À monomers. The peak at around 710 cm À1 indicated an out-of-plane bending mode of borate (BO 3 ) 3À triangular units.…”