Magnetic nanoparticles in different media: effects and impact

Datum

03.06.2014

Zeit

16:40 - 18:10

Sprecher

Prof. Dr. Rainer Birringer

Zugehörigkeit

Universität des Saarlandes

Serie

TUD Physikalisches Kolloquium

Sprache

en

Hauptthema

Physik

Andere Themen

Physik

Host

Prof. Dr. Carsten Timm, Fachrichtung Physik

Beschreibung

Magnetic-field-assisted self-assembly of iron nanoparticles is shown to result in the formation of nanoscale rods. The cooperative behaviour of those rods exhibits self-organized pattern formation on different length scales depending on the magnetic field strength. Pattern formation on large length scales reveals great similarity with physical systems undergoing spinodal decomposition. The incorporation of magnetically hard nanoparticles in a gel matrix, so-called ferrogels, render this materials sensitive to externally applied magnetic fields. We discuss translational, rotational and torsional degrees of freedom of movement of ferrogels stimulated by external field application. Magnetic nanorods which are dispersed in fluids or gels can be used to study the rheology of such soft matter systems on a local scale. We discuss the determination of the local shear modulus of gels. Nanocrystals embedded in a matrix of grain boundaries represent a nanostructured polycrystalline material involving randomness and disorder. We are interested in the influence of randomness and disorder on the second order para- to ferromagnetic phase transition of nanostructured Gadolinium. In particular, we focus on whether or not disorder and randomness may render the fixed point of Gd, which is a 3d uniaxial dipolar ferromagnet, unstable.

Links

• http://tu-dresden.de/veranstaltungen/termin?id=TUD5363a90cb733d

Letztmalig verändert: 03.06.2014, 09:41:00