From the Periodic Properties of Metals to the Rietveld Refinement of the Pharmaceutical Molecule Naproxen: Three Remote Experiments about X-ray Diffraction

Abstract

Recently there is an increasing need for experiments that can be conducted remotely. In this sense, this paper presents three experiments about materials science and an X-ray diffraction (XRD) technique that can be taught and performed entirely remotely. The first experiment is about the calculation of lattice parameters, atomic radii, and densities of metallic elements with a body-centered cubic (BCC) structure. The second experiment is about the calculation of lattice parameters, axial ratios, unit cell volumes, and densities of yttria-stabilized zirconia (YSZ) solid solutions. The third experiment is about applying the Rietveld refinement technique to distinguish the enantiomers of the pharmaceutical molecule naproxen and determine the hydration degree of commercial naproxen sodium pills. For the first two experiments, students worked with simulated data, whereas for the third one, they worked with experimental data collected and provided by the Instructor. Besides the materials science and XRD concepts, students were introduced to the operation of the free softwares Vesta and GSAS II and to the Crystallography Open Database, a free database for structural data of organic and inorganic compounds. The paper explains the background, goals, and results obtained by the students in each one of the experiments. Detailed information about the experimental procedures and their implementation is complemented by the Supporting Information file and Supporting Videos. Although the experiments were presented in an increasing level of difficulty, they are independent of each other, allowing the instructors to apply them according to their needs and learning objectives.