Nanostructured materials are at the forefront of materials science due to their unique physical features. To characterize their microscopic characteristics, a variety of approaches can be used, each with its own set of advantages and disadvantages.
Jenő Gubicza of ELTE Eötvös Loránd University in Budapest explains in a paper published in The European Physical Journal Special Topics that one indirect approach, X-Ray diffraction line profile analysis (XLPA), is acceptable for analyzing nanostructured materials, but that its application and interpretation need additional attention for reliable results.
Nanostructured materials are made of nanoscale grains with a regular atomic lattice. “Defects,” which are sudden changes in the configurations of atoms in these lattices, give rise to useful features. Researchers are able to manage the density of these defects to fine-tune the material characteristics of a nanostructure by choosing the right processing conditions for nanomaterials.
XLPA examines how X-Rays are diffracted by the microstructures included in the materials as they pass through to compare the defect densities created by each of these procedures. The question here is whether the defect structural information acquired by XLPA is accurate, given that this technology only investigates the material indirectly through X-Ray scattering.
Alternatively, transmission electron microscopy (TEM) can offer extremely detailed images of these microstructures, but it can only be utilized to analyze tiny volumes.
Gubicza compares the microstructures identified indirectly by XLPA with those acquired directly by TEM in his study. On one hand, Gubicza discovered that the defect densities calculated by the two approaches are very similar. However, while the grain sizes determined by both approaches differed in materials with greater grain sizes, they mainly agreed for grain sizes less than 20 nm.
In these situations, XLPA properly demonstrated that both top-down and bottom-up nanomaterial processing techniques may yield large fault densities. Overall, Gubicza’s summary provides researchers with important information on how and when to employ XLPA.
Gubicza, J. (2022) Reliability and interpretation of the microstructural parameters determined by X-ray line profile analysis for nanostructured materials. The European Physical Journal Special Topics. doi.org/10.1140/epjs/s11734-022-00572-z.