Modern Physics

X-ray fluorescence and Moseley's law with the multi channel analyser

Principle

The irradiation of strontinum (sulphate), cadmium, indium, iodine and barium (chloride) with soft gamma-radiations gives rise to Ka radiations characteristics of these elements. The X-rayspectra are recorded with a gamma spectrometer consisting of a ...

Hall effect in p-germanium (with the teslameter)

Hall effect in p-germanium (with Cobra3)

Principle

The resistivity and Hall voltage of a rectangular germanium sample are measured as a function of temperature and magnetic field. The band spacing, the specific conductivity, the type of charge carrier and the mobility of the charge carriers are deter ...

Hall effect in n-germanium (with the teslameter)

Hall effect in n-germanium (with Cobra3)

Principle

The resistance and Hall voltage are measured on a rectangular strip of germanium as a function of the temperature and of the magnetic field. From the results obtained the energy gap, specific conductivity, type of charge carrier and the carrier mobili ...

Band gap of germanium

Principle

The conductivity of a germanium test piece is measured as a function of temperature. The energy gap is determined from the measured values.

Tasks

1. The current and voltage are to be measured across a germanium ...

Band gap of germanium (with Cobra3)

Principle

The conductivity of a germanium test piece is measured as a function of temperature. The energy gap is determined from the measured values.

Tasks

1. The current and voltage are to be measured across a germanium ...

Atomic Resolution of the graphite surface by STM (scanning tunnelling microscope)

Principle

Approaching a very sharp metal tip to an electrically conductive sample by applying a electrical field leads to a current between tip and sample without any mechanical contact. This so-called tunneling current is used to investigate the electronic top ...

Investigate in surface atomic structures and defects of diffrent samples by STM

Principle

Scanning tunneling microscopy is used to image the (electronic) topography of different samples on a nanoscopic scale. By scanning across the surface and using analyze tools atomic arrangements, charge density waves and defects are measured and evalua ...

Nanoscale workfunction measurements by scanning tunneling spectroscopy

Principle

Scanning tunneling microscopy is used to image the (electronic) topography of a freshly prepared graphite (HOPG) and gold surface. By spectroscopic measurements (I-z) the local effective work function can be determined in dependence of the material an ...

Nanoscale electrical charakteristics of different samples by STS

Principle

The tunneling current between a very sharp metal tip and an electrically conductive sample is used to investigate the current-voltage characteristics at a nanoscopic scale. The bandstructure of gold, graphite (HOPG) and MoS2 are investigated.

Quantum Mechanics by STM - Tunneling Effect and Charge Density Waves

Principle

In addition to the tunneling effect measured by tunneling spectroscopy another quantum mechanical effect the charge density waves are investigated for different samples. Charge density waves are modulated electron waves due to static and periodic latt ...

Roughness and nanomorhology of different metal samples using by STM

Principle

Approaching a very sharp metal tip to anelectrically conductive sample byapplying a electrical field leads to acurrent between tip and sample withoutany mechanical contact. This so-calledtunneling current is used to investigatethe electronic topograph ...

Counter tube characteristics

Principle

The counter tube uses the ionising effect of high-energy radiation in order to measure the intensity of the radiation. The counter tube characteristics describe its working range, i.e. the voltage range in which it reliably counts the incoming partic ...

Radiographic examination of objects

Principle

An X-ray tube produces X-rays that cause a fluorescent screen to emit light. Objects that are located between the X-ray source and the fluorescent screen will be irradiated so that their inner structure becomes visible. If one varies the anode current ...