The lattice contraction of UO2 from Cr doping as determined via high resolution synchrotron X-ray powder diffraction

Abstract

High resolution synchrotron powder X-ray diffraction analysis of Cr-doped UO2 samples with additions of Cr2O3 as 0, 500, 1000, 1500, 2500 to 3500 ppm prepared under sintering conditions of -420 kJ/mol and 1700 °C is reported. The lattice dependence from Cr doping is established through the Rietveld refinement method where the rate of linear lattice parameter contraction from Cr doping, Δacr, was found to be considerably smaller and more subtle than previously described. This investigation highlights the need for high resolution and precise specimen preparation when measuring and interpreting subtle changes to nuclear material crystal structures due to trace doping.