Principle

A polycrystalline powder sample of lead dioxide is irradiated
with the radiation from a X-ray 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 Debye-Scherrer pattern is
automatically recorded. The evaluation of the pattern not only
allows the Bragg reflexes to be assigned to the individual lattice
planes and so also the corresponding Bravais lattice type to be
obtained, but in addition results in values for their spacing as
well as for the lattice constant of lead dioxide and the number of
atoms in the unit cell.

Tasks


Record the intensity of the Cu X-rays back scattered by a lead
dioxide powder sample as a function of the scattering angle.

Calculate the lattice constant of the substance from the
angular positions of the individual Bragg lines.

Assign the Bragg reflexes to the respective planes of the lead
dioxide lattice and determine which Bravais lattice type it
has.

Determine the number of atoms in the unit cell.


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