Research Projects: Advanced Scattering Techniques

Grazing Incidence Small Angle X-Ray Scattering (GISAXS)

To detect a lateral surface or interface roughness, lateral correlations, sizes and shapes of objects such as particles positioned on top of the surface or in an surface near region off-specular scattering is required. Usually information about in-plane structures are investigated with conventional diffuse (or off-specular) X-ray scattering. Due to a relaxed resolution in one of the three components of the scattering wave vector, these experiments are possible in laboratory based experimental set-ups. Compared to reflectivity measurements the demand for a high primary intensity is increased al-ready. As a consequence of the quite complex data fitting procedure required to extract the desired information from conventional diffuse scattering data, grazing incidence small angle scattering (GISAS) experiments receive an increasing attention within the last years. In case of many sample systems GISAS enables an easy access to the desired structural information, because the Fresnel transmission functions enter only as scaling factors. GISAS involves a combination of two techniques, GID (grazing incidence diffraction), which uses a reflection geometry to obtain surface and near surface sensitive scattering, and SAS (small angle scattering), which measures structures of 1 - 100 nm length in normal transmission mode. It is a non-destructive structural probe and does not require a special sample preparation. GISAS yields an excellent sampling statistics (averages over macroscopic regions to provide information on nanometer scale) and provides information on particle geometry, size distributions and spatial correlations. In GISAS experiments however, the high demand on collimation makes the use of high flux sources of large scale facilities such as synchrotron radiation advantageous. In addition, experiments were successfully per-formed with neutrons at high flux neutron reactors. Thus comparable to reflectivity measurements and conventional diffuse scattering, two probes namely X-rays and neutrons are available. Recently, micro-beam GISAXS experiments enabling a local resolution become possible picture the ongoing experimental developments in the field of GISAS.

Selected Publications:

  • P.Müller-Buschbaum, P.Vanhoorne, V.Scheumann, M.Stamm
    Observation of nano-dewetting structures;
    Europhys.Lett. 40, 655 (1997)
  • P.Müller-Buschbaum, J.S.Gutmann, R.Cubitt, M.Stamm
    Probing the in-plane composition of thin polymer films with grazing-incidence small angle scattering and atomic force microscopy;
    Colloid Polym Sci 277, 1193 (1999)
  • P.Müller-Buschbaum, J.S.Gutmann, M.Stamm, R.Cubitt, S.Cunis, G.von Krosigk, R.Gehrke, W.Petry
    Dewetting of thin polymer blend films: Examined with GISAS;
    Physica B 283, 53 (2000)
  • P.Müller-Buschbaum, S.V.Roth, M.Burghammer, A.Diethert, P.Panagiotou, C.Riekel
    Multiple-scaled polymer surfaces investigated with micro-focus grazing incidence small-angle x-ray scattering;
    Europhys.Lett. 61, 639 (2003)
  • P.Müller-Buschbaum
    Grazing incidence small-angle x-ray scattering - an advanced scattering technique for the investigation of nanostructured polymer films;
    Anal.Bioanal.Chem. 376, 3 (2003)
  • P.Panagiotou, E.Bauer, S.Loi, T.Titz, E.Maurer, P.Müller-Buschbaum
    Polymeric structures at interfaces: An X-ray scattering study;
    Z. Kristallogr. 219, 210 (2004)
  • P.Müller-Buschbaum, S.V.Roth, M.Burghammer, E.Bauer, S.Pfister, C.David, C.Riekel
    Local defects in thin polymer films: A scanning sub-microbeam grazing incidence small angle scattering investigation;
    Physica B 357, 148 (2005)
  • P.Müller-Buschbaum, E.Bauer, S.Pfister, S.V.Roth, M.Burghammer, C.Riekel, C.David, U.Thiele
    Creation of multi-scale stripe-like patterns in thin polymer blend films;
    Europhys. Lett. 73, 35 (2006)
  • P.Müller-Buschbaum, E. Bauer, E.Maurer, K.Schlögl, S.V.Roth, R.Gehrke
    A new route to large-area ordered polymeric nano-channel arrays;
    Appl.Phys.Lett. 88, 083114 (2006)