When 3:30 PM - 5:00 PM Nov 19, 2010
Where 1670 CSE
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Controlling and Manipulating Ferromagnetism with an Electric Field Using Multiferroic Oxide Heterostructures

Alamgir Karim, Department of Polymer Engineering, University of Akron

Orientation control of block copolymer (BCP) films is important for advanced technological applications such as next generation nanoscale lithography. We present some  novel techniques – nanoparticle roughened surfaces utilizing a flexible elastomeric PDMS films to control the orientation of micro-phase separated poly(styrene)-block-poly(methylmethacrylate) (PS-PMMA) cylinder forming BCP films. Although the alkyl chain coated nanoparticles, and crosslinked PDMS have low surface energy, their surface energies can be tuned by exposing to UV-Ozone (UVO) from hydrophobic to hydrophilic. In particular, this presents an opportunity to change BCP-PDMS interfacial energy to control BCP orientation at the BCP air interface. The BCP films were sandwiched between surface energy tunable silica xerogel substrates while conformally contacting crosslinked PDMS elastomer during annealing. The tunable interfacial energies of the top and bottom substrates allowed the BCP films to respond in its orientation of cylinders from parallel to perpendicular. Upon annealing, the PDMS film was easily delaminated from the top glassy BCP film surface without disturbing the surface morphology. The morphology of these micro-phase separated BCP films was studied using phase imaging by tapping mode atomic force microscopy (AFM) and neutron reflectivity (NR).

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