Laboratory for Surface Modification (LSM)

Seminars Archives

August 2018 | September 2018 | October 2018

Thursday, September 13, 2018
Surprises and Puzzles with Ionic Liquids
Robert Hayes
Rutgers University
12:00 Noon - CHEM 260

Ionic Liquids (ILs) are an emerging class of electrolytes composed entirely of ions. ILs remarkable and tunable liquid properties mean they have distinct performance advantages over conventional solvents in many settings. However, current the use of ILs in is hindered by the lack of a systematic understanding of the physical organization of ions in solution, and their associated dynamics. In this presentation, I will highlight some recent experiments in my lab using Atomic Force Microscopy and neutron scattering to close this knowledge gap and yield deeper insight of the nature of the (ionic) liquid state.
Thursday, September 20, 2018
Controlling Domain Wall Dynamics as a Route Towards New Functionalities in Ferroelectric Thin Films
Leo McGilly
Columbia University
12:00 Noon CHEM 260

Domain walls in ferroic materials have promised for a number of years to be the next generation elements in nanoelectronic devices owing to their interesting functional properties, small size and high mobility. While there were numerous studies reporting the dynamics of domain walls there was a notable lack of ability to control their nucleation and motion. To address this point we reported methods that in part sought to rectify some of these issues and so allowed for a degree of control over the dynamics of 180 degree domain walls in PZT thin films using a combination of piezoresponse force microscopy and electron beam induced deposition of high resistivity Pt electrodes. More recent efforts have successfully used focused ion beam microscopy using low dose Ga ions to locally change the domain nucleation sites, coercive fields and rates of switching with high spatial precision through creation of nanoscale defect regions. This defect engineering is a useful tool for fundamental ferroelectrics research as well as leading a way towards potential domain wall nanoelectronics.
Thursday, September 27, 2018
Synthesis of Nanomaterials in Atmospheric Pressure Arc Discharge
Yao-Wen Yeh
Princeton Institute for the Science and Technology
of Materials (PRISM)
12:00 Noon CHEM 260

Arc discharge has been utilized as a method to synthesize various nanostructures since the discovery of C60. Due to its unique synthesis environment (high temperature and atmospheric pressure) and low setup cost, the method has been used to routinely synthesize carbon nanotubes and to explore the synthesis of born nitride nanotubes. However, despite the success of producing these technological important nanomaterials, arc discharge is also known for low synthesis controllability as the material synthesis mechanisms in arc discharge remain elusive due to the complex processes presented in the synthesis environment. In this presentation, I would like to share recent progress made in understanding the synergistic roles of plasma and materials processes in arc synthesis of carbon and boron nitride nanotubes using ex-situ microscopy [1,2], advanced laser technique [3], and molecular dynamics modeling [4].

1. Y. Yeh, Y. Raitses, and N. Yao. Carbon 105 (2016) 490
2. Y. Yeh, Y. Raitses, B. E. Koel, and N. Yao. Sci. Rep. 7 (2017) 3075
3. A. Gerakis, Y. Yeh, M. Shneider, J. Mitrani, B. Stratton, and Y. Raitses. Phys. Rev. Appl. 9 (2018) 014031
4. B. Santra, H. Ko, Y. Yeh, F. Martelli, I. Kaganovich, Y. Raitses, and R. Car. Nanoscale (accepted)

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