ElectronenMikrosonde

ElectronenMikrosonde, also known as an electron probe microanalyzer (EPMA), is an analytical tool used for the elemental and chemical characterization of solid materials. It utilizes a focused beam of high-energy electrons to interact with a sample. This interaction generates various signals, primarily characteristic X-rays, which are then detected and analyzed.

The principle of operation involves bombarding the sample surface with electrons from an electron gun. These electrons penetrate the sample, causing the excitation of atoms within the material. When these excited atoms return to their ground state, they emit X-rays with energies specific to the elements present. An energy-dispersive (EDS) or wavelength-dispersive (WDS) spectrometer is used to measure the intensity and energy distribution of these emitted X-rays.

By analyzing the wavelengths or energies of the X-rays, the elemental composition of the sample can be determined quantitatively. EPMA is capable of detecting elements from beryllium upwards in the periodic table, with detection limits typically in the parts per million range. It can also provide information about the chemical state of elements, such as oxidation states, through subtle shifts in X-ray peak positions.

EPMA is a non-destructive technique, meaning the sample is generally not altered by the analysis. Its applications are widespread across various scientific disciplines, including geology, materials science, metallurgy, and forensics. It is used for tasks like identifying unknown materials, analyzing mineral compositions, studying diffusion processes, and characterizing the microstructure of alloys. The spatial resolution of EPMA is typically in the micrometer range, allowing for analysis of small features and phases within a sample.