Magnetic measurements constitute a promising method for the characterization of nuclear waste glasses in view of their simplicity and small sample weight requirements.
Initial studies of simulated high-level waste glasses show that the Curie constant is generally a useful indicator of the Fe2+:Fe3+ ratio. Glasses produced by air-cooling in large vessels show systematic deviations between experimental and calculated values, which are indicative of the presence of small amounts of crystalline iron-containing phases. Most of the iron in these phases becomes dissolved in the glass upon re-heating and more rapid quenching. The studies further show that upon leaching the glass in water some of the iron in the surface regions of the glass is converted to a form which has high temperature-independent magnetic susceptibility.