The structural role of lanthanum and yttrium in aluminosilicate glasses: a 27Al and 17O MAS NMR study

Research was conducted to examine the structural role of lanthanum (La) and yttrium (Y) in aluminosilicate glasses. HIgh-resolution 17O and 27 Al NMR data on a series of La and Y aluminosilicates demonstrate the significant increase in concentrations of AlO5 and AlO6 groups resulting from the smaller radii and higher field strengths of the modifier cation. Results suggest major effects on network speciation that vary considerably from Y to La and that place new constraints on the type and extent of compositional clustering.