Laboratory-based correlated X-ray imaging and scattering of inhomogeneous glass-ceramics

Abstract

Nuclear waste glasses often contain complex microstructures, and understanding these are key to predicting and engineering glass durability, since heterogeneity may exist over multiple length scales. Here we use laboratory-based, spatially-resolved X-ray characterization methods that span length scales: Wide angle X-ray Scattering (WAXS) provides atomic-scale crystallography; Small Angle X-ray Scattering (SAXS) provides nanoscale phase data; X-ray Computed Tomography and projection X-ray radiography map the materials structure over the micrometer and millimeter scales. The pairing of X-ray radiography with SAXS/WAXS in the same instrument enables specific regions on the sample to be characterized with precise spatial resolution. Two molybdenum- and lanthanum-containing simulated nuclear waste glasses were examined, enabling exploration of hierarchal glassy phase separation and spatial partitioning of crystals of powellite and zircon of different morphologies and sizes 10 nm to 1 mm. The tools described in this study offer means of broadly understanding multi-scale structural attributes of multi-phase materials.