Ph.D. Defense: Alejandra Lopez-Santiago

    Monday, November 24, 2014 - 2:00pm
    Franken Conference Room (Meinel 821)

    "Magneto-optic Polymers and Devices"


    For several decades, the field of magneto-optics has demonstrated applications that have impact on everyday applications such as in optical data storage, magnetic field sensing, magnetoencephalography and magnetocardiography, and compact and efficient optical isolators, among others. In the past, many of these applications and the devices designed for them have heavily relied on inorganic materials. Organic materials with a high MO response represent an interesting alternative to the inorganic equivalent by not only being a more cost-efficient solution, but also by allowing the user to modify a number of variables to control and optimize the MO performance depending on the application and level of performance desired.

    In this dissertation, the presenter discusses the MO properties of novel organic materials, starting with polythiophene, which has been of interest due to the strong relationship between its high MO performance and its lamellar structure and regioregularity.

    She will also be discussing another material system that provides several degrees of MO tunability: magnetite-based nanocomposites. A unique and novel synthetic approach described in this dissertation yields both highly transparent and MO responsive polymer films. She will describe a systematic approach that indicates a strong influence of the size of the nanoparticle as well as the nanoparticle concentration in the MO performance of the bulk polymer, while maintaining high optical quality with minimal scattering and absorption in the visible and near-infrared.

    Finally, she will be discussing the implementation of both a magnetite nanocomposite and a cobalt-ferrite-based nanocomposite in a free-space magnetic field system and demonstrate the proof-of-principle operation of a sensing system.