Density Studies on the Function of Rare‐Earth tons in Glass Matrices

Abstract

The effect on density of the inclusion of low concentrations of rare‐earth ions in lead silicate, soda‐lime, and phosphate glass matrices has been studied. Significant changes are noted in these density values that are particularly noticeable in phosphate glasses and least noticeable in lead glasses. It is considered that the variable function of the Pb2+ ion obscures the general effect of rare earths in lead silicate glasses; but in soda‐lime, and more specifically in phosphate glasses, evidence is highly satisfactory that the lanthanons (La through Lu) function only as network modifiers, and that scandium and yttrium in concentrations of >0.2 and 1.0 atomic % function strongly as network formers. This is shown to be in accord with concepts associating glass function with cation electronegativity.