Regensburg 2007 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 31: New Materials
CPP 31.8: Vortrag
Freitag, 30. März 2007, 12:15–12:30, H40
Magnetic and structural properties of thin polymer films with embedded superparamagnetic γ-Fe2O3 nanoparticles — •L. Schulz1, S. Vallopilly2, J. Perlich1, M.M. Abul Kashem1, S.V. Roth3, and P. Müller-Buschbaum1 — 1TU München, Physik-Department LS E13, James-Franck-Str. 1, 85747 Garching, Germany — 2LENS, Indiana University Cyclotron Facility, 2401, Milo B. Sampson Lane, Bloomington, IN 47408, USA — 3HASYLAB at DESY, Notkestr. 85, 22603 Hamburg, Germany
We investigate lamellae-forming polystyrene-b-polyisoprene diblock copolymer films with embedded γ-Fe2O3 nanoparticles. The used block copolymer is asymmetric and forms a microphase separation structure. For the thin film preparation we apply two techniques, spin coating and solution casting. Magnetisation measurements at 2 K and 300 K show that the saturation magnetisation is linear dependent on the nanoparticle concentration. A constant coercitive field and increasing fields of remanence for different nanoparticle concentrations are verified. AC-susceptibility measurements exhibit non-interacting superparamagnetic behaviour of the nanoparticle ensemble. Ageing effects confirm spin-glasses in the surface of the nanoparticles. Structural composition and distribution of the nanoparticles within the thin films are obtained by grazing incidence small angle X-ray scattering (GISAXS) and X-ray reflectivity. An increasing nanoparticle concentration results in forming smaller characteristic structure sizes. GISAXS experiments are performed at beamline BW4 at HASYLAB/DESY in Hamburg.