2011, Arzt, Eduard, Moh, Karsten, Cavelius, Christian, Mandel, Karl, Dillon, Frank, Koos, Antal A., Aslam, Zabeada, Jurkschat, Kerstin, Cullen, Frank, Crossley, Alison, Bishop, Hugh, Grobert, Nicole

Monodisperse, size-controlled Ni–P nanoparticles were synthesised in a single step process using triphenyl-phosphane (TPP), oleylamine (OA), and Ni(II)acetyl-acetonate. The nanoparticles were amorphous, contained 30 at% P and their size was controlled between 7–21 nm simply by varying the amount of TPP. They are catalytically active for tailored carbon nanotube growth.

2021, Müssig, Stephan, Kuttich, Björn, Fidler, Florian, Haddad, Daniel, Wintzheimer, Susanne, Kraus, Tobias, Mandel, Karl

The controlled agglomeration of superparamagnetic iron oxide nanoparticles (SPIONs) was used to rapidly switch their magnetic properties. Small-angle X-ray scattering (SAXS) and dynamic light scattering showed that tailored iron oxide nanoparticles with phase-changing organic ligand shells agglomerate at temperatures between 5 °C and 20 °C. We observed the concurrent change in magnetic properties using magnetic particle spectroscopy (MPS) with a temporal resolution on the order of seconds and found reversible switching of magnetic properties of SPIONs by changing their agglomeration state. The non-linear correlation between magnetization amplitude from MPS and agglomeration degree from SAXS data indicated that the agglomerates' size distribution affected magnetic properties.