Coordination state of aluminum and boron in barium aluminoborate glass

Abstract

This paper considers the coordination state of boron and aluminum ions in barium aluminoborate glass with a constant ratio of BaO: B₂O₃ = 0.5 and a variable ratio of Al₂O₃: BaO = 0–3. The dependence of the concentrations of boron and aluminum atoms with a variable coordination number on the Al₂O₃ content was estimated by IR, ¹¹B and ²⁷Al NMR spectroscopy. The nonlinear nature of the obtained dependences was attributed to variations in the aluminum oxide properties. At a content of less than 30 mol % Al₂O₃ serves primarily as a network former, while an increase in the Al₂O₃ concentration results in its higher modifying role in the studied glass.