Characterizing Heterogenous Defect Structures in Spinel Oxides Disordered via Extreme Conditions

The development of advanced energy technologies requires carefully designed materials for use in harsh operating conditions, such as high temperatures, high pressures, and extreme radiation fields. Complex oxides are promising candidate materials for use in such advanced energy technologies; however, they are prone to disorder and defects which form during exposure to these extremes. Over time, such structural modifications build up and modify the properties of materials and eventually lead to their degradation. Thus, understanding the underlying atomic-scale mechanisms of defect formation is essential to, not only predict how these materials degrade, but also to develop new, more robust materials. Using neutron total scattering, both the long-range coherent structure and the local atomic arrangements can be measured simultaneously, with high sensitivity to both cations and anions; this presents a great advantage over more conventional characterization techniques. Neutron scattering has been used to analyze the unique local defect structures in spinel disorder through high temperature and through intense ionizing irradiation. Preliminary work was also performed, to expand this scattering technique to enable the study of materials disordered through high pressure.