Date: Thursday, February 6, 2014
Time: 11:00 am
Speaker: Dr. Alexandros Lappas, Institute of Electronic Structure and Laser, Crete, Greece
Title: Properties and Applications of Surface-stabilised Iron-Oxide Magnetic Nanoclusters
Location: 67-3111 Chemla Room
Multifunctional iron-oxide nanocrystals pave the way for solutions in problems of practical importance to the society, ranging from electronics to diagnosis and therapy.
In view to this, we employ modular colloidal chemistry approaches for the surface stabilization of tailored-made nanocrystals which further allows their neat growth in size-tunable cluster-like particle ensembles. While a dilute system based on such particles apparently may be easier to understand, dense systems can be a subject of debate as mutual particle interactions are not that easy to disentangle. These assemblies of nanoparticles are probed by complementary experimental (HRTEM, ac/dc magnetometry, optical and NMR spectroscopies) as well as theoretical (Monte Carlo) methods. Proximity effects manifest themselves in cooperative physical phenomena, otherwise not observed from non-interacting particle ensembles. We illustrate that the knowledge and contribution of the different length-scale microscopic mechanisms are crucial for engineering functional iron-oxide nanoarchitectures for magnetically-driven applications. The diverse technological potential of such nanoparticle-assembled systems is drawn with respect to their capacity to operate as magnetically tunable photonic crystals as well as their impact in MRI contrast enhancement and hyperthermia efficacy.