New magnetic nanomaterials

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Magnetic materials are routinely used in daily life, from cute refrigerator magnets to computers and state-of-the art magnetic resonance imaging in hospitals. Smaller materials are advantageous, as they result in smaller, faster, and more energy efficient computers, and in the human body creep in all the nooks and crannies for better diagnostics and efficient drug delivery. We study how we can improve our daily lives by making new nanoscaled materials, and benchmarking them against current state-of-the-art materials used in information technology and biomedical analysis. Through this research program, we will prepare and study new magnetic nanomaterials with novel properties, and further our understanding of magnetism at the nanoscale. The performance of spintronic devices found in all modern computers relies on the spin polarization of their magnetic components. Materials predicted to have 100% spin polarization (eg Co2MZ [M= Fe,Cr,Mn, Z=Al,Si,Ge]), would be advantageous as nanostructures to miniaturize and speed up devices. We will design synthetic avenues to Co2MZ nanomaterials, and evaluate their properties as a function of size, composition, and morphology. Gold, a non-magnetic material in the bulk, exhibits permanent magnetism, at room temperature, when in the form of thin films or nanocrystals (~5nm or less) modified with thiol self-assembled monolayers. We will study the impact of nanocrystal size, shape, and chemical identity of the monolayer on the magnetic properties of these nanocrystals. In particular, functionalization with a photochromic switch such as a thiolated azobenzene is pursued, wherein the photochrome's state leads to large modifications of the magnetic properties. To obtain single-phase ferromagnetic, luminescent, and biocompatible nanomaterials, we will dope Al2O3, a material recently shown to be ferromagnetic when nanoscaled, with luminescent lanthanide ions. Synthetic avenues towards the controlled incorporation of the lanthanide ion into the host will be devised.