Structural impact of cobalt ions on BaBiBO4 glass system by means of spectroscopic and dielectric studies

► Structural properties of BaBiBO4:CoO glasses were studied. ► At low concentration of dopant, tetrahedral CoO4 units are formed with high rigidity. ► In C20 glass, Bi3+ ions are reduced to Bi2+ ions with Co2+ ions as reduction partners. ► NBOs, BO3, BiO6 and CoO6 symmetry units are favored at higher CoO wt%.