Cathodoluminescence microscope

A Kathodolumineszenzmikroskop is a combination of an optical microscope with a cathode ray tube. It is used to investigate the excited by an electron beam luminescence ( cathodoluminescence ) of polished thin sections of solid samples. To prevent charging of the sample surface must be coated with a thin conductive layer made ​​of gold or carbon. This is usually accomplished by coating the plasma in a sputter device or vapor deposition with carbon.

Using a Kathodolumineszenzmikroskops structures within the crystals or the structure can be made visible, which are not recognizable under normal light microscopic conditions. For example, important information about the growth of crystals can be obtained. Kathodolumineszenzmikroskope be in geology, mineralogy, and materials science used ( study of rocks, minerals, volcanic ash, glass, ceramics, cement, fly ash, etc.). Color and intensity of the cathodoluminescence are essentially dependent on the properties of the sample, but are also strongly influenced by the working conditions of the electron source is determined ( accelerating voltage and beam current of the electron beam ).

Today, two types Kathodolumineszenzmikroskopen are in use. One operates with a "cold cathode" wherein the electron beam is generated by a gas discharge tube. The other generates an electron beam by means of a hot cathode (English " hot cathode " ), where the electrons are accelerated by an incandescent tungsten wire ( hairpin cathode) from. The advantage of a hot cathode is the high and precisely controllable intensity of the electron beam, which also weakly luminescent materials ( such as quartz, see figure) can be excited to emit light.

• Light microscopy
• Electron tube
• Optoelectronics