Regensburg 2013 – scientific programme

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CPP: Fachverband Chemische Physik und Polymerphysik

CPP 20: Poster: Colloids and Complex Liquids

CPP 20.22: Poster

Tuesday, March 12, 2013, 18:15–20:15, Poster C

Synthesis of Hematite particles monitored using in-situ SAXS and WAXS — •Alexander Schavkan, Fabian Westermeier, Ingo Steinke, Jan Perlich, Birgit Fischer, Gerhard Grübel, and Michael Sprung — DESY Deutsches Elektronen-Synchrotron, Notkestraße 8, 22607 Hamburg, Deutschland

To study the statistical physics of phase transitions, colloidal suspensions are often used as model systems. Due to their complex phase diagrams, suspensions of anisotropic nanoparticles, like hematite particles, are particularly interesting. These particles can be synthesized with varying size aspect ratios and can be aligned in an external magnetic field. The described experiments aimed to investigate the evolution of the synthesis and the appearance and growth of the magnetic moment during the chemical reaction.

Two syntheses were performed under an applied static magnetic field and monitored using in-situ SAXS and WAXS. While in one of these syntheses the growth of anisotropic, spindle shaped particles was induced by the addition of NaH2PO4, the second chemical reaction yielded isotropic, cubic shaped particles. By SAXS measurements the appearance of a magnetic moment in the particles and the development of the particle size and size distribution was investigated. WAXS experiment monitored the change in the chemical composition of the particles from Iron(III)chloride to hematite (β-Iron(III)oxide).

This contribution shows the details and the results of the experiment.