Scanning electron microscopy (SEM) at GWP
The GWP offers comprehensive investigations using scanning electron microscopes (SEM) to carry out high-precision analyses of solid surfaces. Thanks to the SEM's high depth of field, surface structures can be imaged and analyzed in great detail. A tungsten cathode is used to generate an electron beam that scans the surface of the sample in a high vacuum. The resulting interaction products provide detailed image information about the surface structure.
Possible applications of REM in GWP:
- imaging by secondary and backscattered electron contrast: These methods enable the detailed representation of fracture surfaces, topographies and material contrasts.
- High resolution in the nanometer range: With a magnification of up to 50.000 times, even the finest surface details can be made visible.
- low-vacuum operation: Samples can be examined at a pressure of 1 to 270 Pa without the need for a conductive coating (e.g. gold or graphite).
- EDX elemental analysis: By detecting characteristic X-rays with a silicon drift detector, the chemical elements of the sample can be analyzed qualitatively and semi-quantitatively.
- Large sample chamber: Samples with a diameter of up to 200 mm, a height of 70 mm and a weight of up to 2 kg can be examined.
REM detectors and their applications:
- SE detector (secondary electrons): Here, topographic contrasts arise through the interaction of the electron beam with the sample, which are particularly used for the investigation of surface structures such as fracture surfaces, corrosion or surface quality.
- RE detector (backscattered electrons): This technique enables the representation of material contrasts, since the backscattered electron energy depends on the density of the material. Impurities, layer systems and inclusions can be made visible in this way.
- EDX detector (energy-dispersive X-ray spectroscopy): This method enables the chemical analysis of the sample. In addition to point and integral analyses, line scans and mappings can also be created to graphically display the distribution of chemical elements. The mapping function in particular provides clear information about the composition in relation to the structure of the sample.
SEM color images: Since SEM images are displayed in grayscale by default, GWP offers professional image processing to colorize these images afterwards. This highlights certain features and conveys complex information in a clear manner. This method is often used in medical technology and pharmaceuticals in particular to better visualize specific details.
Scanning electron microscopy at GWP enables precise and versatile examination of samples for various industrial sectors, such as materials science, medical technology or pharmaceuticals.
