Institut für Chemie



Dr. Stefan Wellert

Email: s.wellert(at)


The Kratky-type instrument SAXSess mc² (Anton Paar) enables the study of structures with small  and wide angle X-ray scattering with sizes ranging from 1nm to 100nm. Different types of samples can be measured, e.g. fluids such as colloidal solutions, solids, such as polymer films, fibers powders, nanocomposites, or biological samples (proteins and macromolecules in solutions).This allows the determination of size, shape and size distribution in particle suspensions, molecular weights of polymer solutions, aggregation behavior, porosity in porous materials or structural properties of polymer films and fiber materials.

Instrument properties

  • X-Ray source: Long-fine focus sealed copper tube with horizontal line focus at 0.1542 nm (Cu Kalpha)
  • Sample-detector distance: 250 to 280 mm.
  • SAXS detector: Princeton Instruments  SCX-4300 CCD: Pixel size 24 micro meter
  • imaging plate 66 × 62 mm (SAXS) or 66 × 200 mm (SWAXS).
  • Sample holders:
  • quartz capillary for liquids (diameter = 1 mm, wall thickness 10 micrometer, sample volume < 50 microliter);
  • film holder – 5 × 20 mm;
  • Rotary sample cell
  • temperature controlled holders TCS 300 and TCS 120 from ambient to +300°C and from -30°C to +120°C.


The D8 diffraction system (Bruker AXS) in reflectometry mode is used to measure thin film samples (e.g. polymer films at silicon wafers) to determine film thickness and interface roughness. Bruker AXS reflectometer is equipped with a Goebel mirrors before the sample. Corresponding to the Cu-Kα1 transition the wavelength of the instrument is 0.1542 nm. In addition to solid planar substrates, also thin liquid films in a Langmuir through can be measured.

Instrument properties

  • X-Ray source: Sealed copper tube with horizontal line focus at 0.1542 nm (Cu Kalpha)
  • Vertical goniometer in 𝜗 - 2𝜗 configuration operated in reflectometry mode
  • Detector: Scintillation counter (wavelength range 0.05 - 0.3 nm)

Sample holders: vertically displaceable sample stage for planar substrates, Langmuir trough for measurements at fluid interfaces