Evidence of Ni-containing ordered domains in low-alkali borate glasses

A noteworthy inhomogeneous distribution of Ni in low-alkali borate glasses has been shown by Ni K-edge EXAFS (Extended X-ray absorption Fine Structure). The first evidence of a multiple scattering feature in a glassy matrix indicates an extended intermediate range order extending up to 6 Angstrom. The Ni-enriched domains consist of corner- and edge-sharing NiO6 octahedra, with three-dimensional connections. The presence of this unusual order in glasses is likely associated with the rigid borate groups present in low-alkali borate glasses.