Lithium Borates from the Glass to the Melt: A Temperature-Induced Structural Transformation Viewed from the Boron and Oxygen Atoms

A multiedge study of the local structure lithium borate glasses and melts has been carried out using X-ray Raman scattering (XRS) as a function temperature. Thanks to wide range compositions, from pure B2O3 up metaborate composition, we are able finely interpret modifications environment both boron oxygen atoms in terms coordination number, formation nonbridging oxygens (NBOs), polymerization degree framework temperature composition. temperature-induced [4]B [3]B conversion is observed above glass transition (Tg) melt triborate composition Two distinct structures reported: well-polymerized network—with few NBOs—below depolymerized network diborate with rapid increase number NBOs when Li2O added. These two structurally allow explaining dynamic regimes for ion diffusion.