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About the seminar:

Magnetic materials find use in a variety of applications, and still offer new surprises in terms of unexcpected physical behaviours. In this talk, I will present our work on two areas of nanomagnetism. First: the design of new nanoparticulate metal-oxide nanomaterials for use as contrast agents in magnetic resonance imaging. Our focus has been in the design of contrast agents for high-field MRI. We investigate several parameters, such as low-molecular weight capping ligands, magnetochemical series across mixed metal ferrites, and the effect of shape in new Mn-based agents.

Second: the study of unexpected, and yet-to-be fully understood magnetism in nanostructures of coinage metals – Cu, Ag, and Au. We took advantage of gas-phase synthesis to creates nanoparticles and thin films free of capping ligands allowing for pristine surface studies. The two types of Cu and Ag nanomaterials synthesized were sub-12 nm diameter nanoparticles and thin films. These three parameters, namely the nature of the coinage metal, unmodified surfaces, and nanodimensionality, were the core effects independently studied. Our findings indicate that ferromagnetic behaviour can be induced in nanoparticles and thin films of these metals as a result of partial oxidation of their surface; thus, there is no size effect linkage to their magnetism. For Au, we show that the capping ligand can tune the magnetism of similarly sized thiolate-coated Au NPs.