Principle

A polycrystalline powder sample of zinc 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 constants of zinc and the number of atoms in the unit
cell.

Tasks


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

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

Assign the Bragg reflexes to the respective planes of the zinc
lattice and determine the Bravais lattice type of it.

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