Deutsche Tagung f ¨ur Forschung mit ... - SNI-Portal

Weiche Materie Poster: Do., 13:00–15:30 D-P351
Structural and magnetic properties of polystyrene-b-polyisoprene diblock
copolymer films with embedded Fe2O3 nanoparticles
L. Schulz 1 , S. Valloppilly 2 , S. V. Roth 3 , M. Burghammer 4 , C. Riekel 4 , P.
Müller-Buschbaum 1
1 TU München, Physik-Department LS E13, James-Franck-Str. 1, 85747 Garching
(Germany) – 2 TU München, Physik-Department LS E21, James-Franck-Str. 1, 85747
Garching (Germany) – 3 HASYLAB at DESY, Notkestr. 85, 22603 Hamburg (Germany)
– 4 ESRF, 6 rue Jules Horowitz, BP220, 38043 Grenoble Cedex (France)
We investigate lamella-forming polystyrene-b-polyisoprene coploymer films with embedded
Fe2O3 nanoparticles. The used block copolymer is asymmetric and forms a
microphase separation structure due to the incompatible block segments PS and PI.
For the thin film preparation we apply two well-known techniques, spin-coating and
solution-casting. From PS-b-PI/Fe2O3 nanoparticles mixtures, dissolved in toluene, we
are able to produce the desired thin polymer films on precleaned Si subtrates. Annealing
induces further self-organisation. Various concentrations of nanoparticles result in
different physical properties of the polymer matrices. Magnetic measurements indicate
superparamagnetic behaviour of the nanoparticles at 300K and a ferromagnetic order at
very low temperatures. In the ferromagnetic state the nanoparticles possess a constant
coercivity irrespective of their volume fraction. Investigations with optical microscopy
on macroscopic and atomic force microscopy (AFM) on microscopic length scale provide
information about the surface. Structural composition, topography and distribution of
the nanoparticles within the thin layers are obtained by grazing incidence small angle
X-ray scattering (GISAXS) and X-ray reflectivity. GISAXS experiments are performed
at beamline BW4 at HASYLAB/DESY in Hamburg and beamline ID13 at ESRF in
Grenoble.