Non-Destructive Investigation of Composition, Chemical Properties and Structure of Materials by Synchrotron Radiation

Synchrotron radiation has (partly unique) properties promoting the investigation of solids and interfaces on a broad scale. This can support the development of new materials among them certified reference materials (CRMs). Due to the high intensity and the minute size of the light source the radiation can be filtered (monochromatized) and/or focussed onto the sample. Samples can be scanned at high resolution (≈ 2 μm) with optimum X-ray energy. Moreover, the high degree of polarization (linear, circular, elliptic) allows to study magnetic properties e.g. of layered structures[1]. Computer assisted tomography (CT) based on X-ray absorption avoids artefacts caused by beam hardening using monochromatic radiation [2]. Refraction of X-rays tells us a lot about interior interfaces, their flaws, their behaviour under load or about the high cycle fatigue of compound materials like carbon fibre reinforced plastics. Refraction or small angle X-ray scattering (SAXS) make use of the high parallelity of the synchrotron light and can be combined with a scanning regime resulting in topographic images of down to submicron resolution [3]. One can learn a lot about surface near regions from electron spectroscopy after excitation by synchrotron radiation [4]. X-ray microscopy within the so called “water window” (between the K-edges of carbon and oxygen) makes tiny biostructures visible [5]. The mentioned group of examples is by far not complete. From the numerous interactions of synchrotron radiation with matter only absorption, reflection and fluorescence will be dealt with in this contribution.