Principle
A polycrystalline, cubic face-centered crystallizing copper
powder sample and a thin copper sheet are separately irradiated
with the radiation from a Roentgen tube with a copper anode. A
Geiger-Mueller counter tube is automatically swivelled to detect
the radiation that is constructively reflected from the various
lattice planes of the crystallites. The Bragg diagrams are
automatically recorded. The evaluation allows the Bragg reflexes to
be assigned to the individual lattice planes. In contrast to the
powder sample, the rolled thin sheet gives a spectrum showing an
alignment of the crystallites (rolled texture), that is made even
more complete by heating the sheet.
Tasks
- Record the intensity of the Cu X-rays back scattered by a cubic
crystallizing copper powder sample as a function of the scattering
angle.
- Assign the Bragg reflexes to the individual lattice
planes.
- Record the Bragg spectrum of a thin sheet of copper.
- Repeat the measurements made in Task 3 after the sheet of
copper has been subjected to annealing.
What you can learn about
- Crystal lattices
- Crystal systems
- Bravais-lattice
- Reciprocal lattice
- Miller indices
- Structure factor
- Atomic scattering factor
- Bragg scattering
- Characteristic X-rays
- Monochromatization of X-rays
- Fiber textures
- Sheet textures
- Annealing texture
- Recrystallization