Table 4 Raman peak positions and associated band assignments of BBBNDy glasses.

~ 65–98

Modes of vibration in Bi³⁺ ions exhibiting E_g symmetry

^63,71

~ 154–199

Bi³⁺ ion vibrations with BiO₃ and BiO₆ structural units, as well as with Bi–O stretching modes

^77,78

~ 244–266

Bi–O–Bi bond vibrations arising from BiO₆ octahedral and BiO₃ pyramidal structural units

^79,80

~ 339–450

Bi–O–Bi bond linkages with BiO₆ structural units, overlapping with the vibrational modes of [BO₃] and [BO₄] structural motifs

^64,81

~ 628

B–O vibrational modes with [BO₄] tetrahedral units and B–O–B linkages, in different borate species

⁷¹

~ 754

Symmetrical B–O stretching modes in BO₄ units, particularly linked to orthoborate groups, are influenced by pyramidal modes of Bi₂O₃

^71,82

~ 1195

Asymmetric B–O stretching modes in terminal [BO₃] motifs, linked with pyroborate structural units

⁸³

~ 1337–1387

Stretching B–O vibrations with tetrahedral [BO₄] units

⁸⁴

~ 1657

Stretching B–O vibrations associated with pyro-borate structural units

⁸⁵