Lee Hsun Lecture Series 

Topic: Monodisperse Magnetic Nanoparticles:Chemical Synthesis and Potential Applications 

Speaker: Prof. Shouheng Sun 

         Vernon K. Krieble Professor of Chemistry 
         Professor of Engineering, Department of Chemistry, Brown University 

Abstract: 

Magnetic nanoparticles are promising building blocks for fabrication of high-performance magnetic materials and highly efficient catalysts for electronic, magnetic, biomedical and energy applications. We demonstrate that monodisperse magnetic nanoparticles of Fe, Co, FePt, CoPt and MFe2O4 (M = Fe, Co, Mn), as well as SmCo5 and Sm2Fe17N3 with controlled size, composition, shape and structure can be synthesized by solution phase chemical reactions and assembled into 2D and 3D magnetic nanoparticle arrays. The texture in self-assembled arrays is established via the control of nanoparticle shape or via assembly under a magnetic field. Magnetic properties of these arrays are tuned from superparamagnetic to ferromagnetic with controlled magnetization and coercivity (up to 5 T). The Pt-based hard magnetic nanoparticles are also a class of robust catalyst for electrochemical reduction of oxygen or oxidation of fuels in polymer electrolyte membrane fuel cells. These well-engineered magnetic nanostructures are of great importance for magnetic data storage, magnetic energy storage and electrochemical energy conversion applications.