IMIC – Hands On Courses – PXRD
Structure of the course
The PXRD Hands-On course was structured into a total of eight individual sequential chapters (learning packages). These chapters were provided within a period of two weeks (Learning packages 0 – 3 in the first and packages 4 – 7 in the second week of the course). The schooling could be done completely independently by the participants themselves, i.e. none of the offered zoom meetings had the purpose of solving the exercises and problems contained in the chapters in a group.
The individual packages were usually structured according to the following principle: A new topic, based on the previous packages, was introduced and the individual steps for solving the problem were learned on the basis of provided guidelines and given examples. At the end of each package, there were one or more tasks that could be solved based on the taught content.
The meetings functioned more as a briefing of the treated exercises, where the students could discuss with the course instructor about their results and encountered problems, also in a smaller scale of breakout sessions. These meetings took place approximately every second day during the two weeks of the course and, in our case, always commenced in the afternoon. However, these meetings were not a mandatory part of the Hands-On course. Participation is recommended as many of the problems that arose could be solved.
In addition to the meetings, there was a discussion forum on Moodle in which the contents could be discussed with the students and the course instructor. It was also possible to share, compare and discuss his results in the forum.
The goal of the course was to learn first experiences in the quantitative analysis of powder diffraction data. Starting with the appropriate visualization of structural data, indexing of powder diffractograms, i.e. the determination of the crystal system and lattice parameters, up to more sophisticated techniques, such as the refinement and determination of a structure based on the powder diffractometry data. In detail the topics were divided into the following chapters: Structure visualization, phase indication, phase indexing, profile matching, structure refinement, solution of the structure and the so-called “exotics” (pressure-dependent and temperature-dependent consideration of the lattice parameters).
During the editing of the packages, many different software’s were used, without the solving of the tasks and thus the participation in the course is not possible. The installation and setup of the programs also caused some complications for some students. At this point it is important to mention that the programs used, currently do NOT run on macOS systems. Apple users should therefore look for a solution before attending the course. The programs that were used in the course are TOPAS Academic, jEdit, WinSPOW, Vesta and Diamond.
Type of examination/final task
As a completion of the PXRD Hands-On course, a short series of questions was provided by the course instructor, which dealt once again with the various topics and issues covered in the program of the course. These questions had to be answered in short, concise answers and using a correct technical language, which had to be sent back to the instructor within a given period of time. Fortunately, this lasted several weeks, so that the students had enough time to give the answers and to review the course content.
This course is primarily addressed at those who want to take their first steps in the field of powder X-ray diffraction, which should certainly concern many of the students, since powder X-ray diffraction is a central technique in inorganic chemistry.
A positive aspect of the course for me is the flexible editing of the tasks since it is up to you to decide when and at what pace you want to work on the topics. You can participate in the Hands-On course without running the risk of scheduling conflicts with other research internships or exams.