Experiment nr. 10

X-Ray diffraction II (only in German)

Supervisor: Dr. habil. Michael Lorenz

In the experiment X-Ray Diffraction II several solid state samples will be analysed using a PHILIPS X'pert diffractometer system.
At first, an introduction will be given on generation and the safety instructions for X-rays. The emitted X-ray lines are correlated to the electronic structure of the atoms of the anode material. Thereby, quantum mechanical phenomena as the spin-orbit coupling become visible in the diffraction patterns. Furthermore, the understanding of basic terms of crystallography as crystal and axis systems, Miller's indices, reciprocal lattice and of practical points of view as the accuracy and errors in the goniometer measurement is aim of the experiment.

The main tasks are:
Determination of the lattice constants of polycrystalline materials with cubic and hexagonal structure.
Investigation of polycrystalline bulk material and grown thin films of the high-Tc superconductor YBa2Cu3O7-d.
Determination of lattice constants, oxygen deficiency and preferential orientation of the thin films.
Understanding of the terms texture and epitaxy.
Determination of the mosaicity of the thin films and correlation with the electrical properties (critical current density).

Attention: mentoring for this experiment only in German