The structure of alkali borate glasses

The structural complexity and diversity of borate glasses attract researchers to unveil these mysteries. When alkali oxide adds to B2O3 glass, the three-coordinated BO3 in boroxol ring transforms into tetrahedral units [BO4]- and part bridging oxygen atoms change into non-bridging oxygen for balancing the positive charge of metal ions. These transformations result in many superstructural units be present in borate glasses. These species can transform between themselves with the changing of composition and metal oxides. Although a large number of experimental efforts have been made to unveil borate glass structures, their details are incompletely understood and new structures are continually observed. The aim is to reveal the mechanism of structural modification of metal ions on borate glasses and the transformation among these superstructures using neutron diffraction and other methods.