Quantitative three-dimensional local order analysis of nanomaterials through electron diffraction
Structure-property relationships in ordered materials have long been a core principle in materials design. However, the intentional introduction of disorder into materials provides structural flexibility and thus access to material properties that are not attainable in conventional, ordered materials. To understand disorder-property relationships, the disorder - i.e., the local ordering principles - must be quantified. Correlated disorder can be probed experimentally by diffuse scattering. The analysis is notoriously difficult, especially if only powder samples are available. Here, we combine the advantages of three-dimensional electron diffraction - a method that allows single crystal diffraction measurements on sub-micron sized crystals - and three-dimensional difference pair distribution function analysis (3D-ΔPDF) to address this problem. 3D-ΔPDFs visualise and quantify local deviations from the average structure and enable a straightforward interpretation of the single crystal diffuse scattering data in terms of a three-dimensional local order model. Comparison of the 3D-ΔPDF from electron diffraction data with those obtained from neutron and x-ray experiments of yttria-stabilized zirconia demonstrates the reliability of the newly proposed approach.