Stephen Ducharme
Professor and Vice Chair
Department of Physics and Astronomy
256 Behlen Laboratory
Phone: (402) 472-8590
Email: sducharme1@unl.edu
Steve Ducharme's Physics Web Page
Current Research
Ferroelectric Polymers: Crystalline Langmuir-Blodgett films of poly vinylidene fluoride and its copolymers as thin as one nanometer are the first truly two-dimensional ferroelectrics and have several potential applications. This work involves a multi-disciplinary collaboration with groups led by V. M. Fridkin at the Institute of Crystallography, Russian Academy of Sciences, Moscow; J. Li at the University of Washington; H. Kohlstedt at the Institut fûr Festkörperforschung in Jülich, Germany; S. Kalinin at Oak Ridge National Laboratory; S. Nakhmanson at Argonne National Laboratory; and the J. A. Woollam Co. Collaborations within the NCMN involve groups led by J. M. Takacs (Chemistry), S. Adenwalla and A. Gruverman (Physics), R. Saraf (Chemical Engineering), and Y. Lu (Electrical Engineering).
Fundamental studies focus on the properties of the ferroelectric polymer LB films, such as, the phase diagram, switching dynamics, dielectric properties, properties of nanostructured films, and development of new ferroelectric polymers. Applied studies focus on the application of the ferroelectric polymer LB films to nonvolatile random-access memories, pyroelectric infrared imaging devices, and high-energy-density capacitors. Notable accomplishments include the discovery of two-dimensional ferroelectricity, the first measurements of the intrinsic ferroelectric coercive field and intrinsic switching kinetics, development of a ferroelectric integrated polymer-silicon nonvolatile access memory element, discovery of ferroelectric nanomesas as small as 10 nm high by 100 nm in diameter.
Recent Publications
"Start the Presses," S. Ducharme and A. Gruverman, Nature Materials 8, 9-10 (2009). Invited "News and Views" article. DOI:10.1038/nmat2348
"Switching Kinetics of Ferroelectric Nanomesas," C. M. Othon, J. Kim, S. Ducharme, V. M. Fridkin, J. Applied Physics 104, 054109 (2008). Also featured in the Virtual Journal of Nanoscale Science and Technology 18 (12), 22 September 2008, http://www.vjnano.org.
"Oligo(vinylidene fluoride) Langmuir-Blodgett films studied by spectroscopic ellipsometry and the density functional theory," R. Korlacki, J. Travis Johnston, Jihee Kim, Stephen Ducharme, Daniel W. Thompson, V. M. Fridkin, Zhongxin Ge, James M. Takacs, J. Chemical Physics 129, 064704.1-4 (2008).
"Local Probing of Relaxation Time Distributions in Ferroelectric Polymer Nanomesas: Time-Resolved Piezoresponse Force Spectroscopy and Spectroscopic Imaging," Brian J. Rodriguez, Stephen Jesse, Jihee Kim, Stephen Ducharme, Sergei V. Kalinin, Applied Physics Letters 92, 232903.1-3 (2008). Also featured in the Virtual Journal of Nanoscale Science and Technology 17 (25), 23 June 2008, http://www.vjnano.org.
"Polarization Switching Kinetics at the Nanoscale in Ferroelectric Copolymer Langmuir-Blodgett Films," R. V. Gaynutdinov, O. A. Lysova, A. L. Tolstikhina, S. G. Yudin, V. M. Fridkin, and Stephen Ducharme, Applied Physics Letters 92, 172902.1-3 (2008). Also featured in the Virtual Journal of Nanoscale Science and Technology 17 (19), 12 May 2008, http://www.vjnano.org.
"The Electric Energy Density of Dielectric Nanocomposites," J. Y. Li, L. Zhang, S. Ducharme, Applied Physics Letters 90, 132901 (2007). Also featured in the Virtual Journal of Nanoscale Science and Technology 15 (14), 9 April 2007, http://www.vjnano.org.
"Low-Voltage operation of metal-ferroelectric-insulator-semiconductor diodes incorporating a ferroelectric polyvinylidene fluoride copolymer Langmuir-Blodgett film," A. Gerber, M. Fitsilis, H. Kohlstedt, R. Waser, T. J. Reece, S. Ducharme, E. Rije, J. Applied Physics 100, 024110 (2006).
"Nanomesa and Nanowell Formation in Langmuir-Blodgett Polyvinylidene Fluoride
Trifluoroethylene Copolymer Films," J. Li, Y. Luo, M. Bai, S. Ducharme, Applied Physics Letters 87, 213116 (2005). Also featured in the Virtual Journal of Nanoscale Science and Technology 12(22), 28 November 2005 http://www.vjnano.org.
Recent Graduates
Jihee Kim, Ph.D., 2008. "Polarization Coupling in Nanostructured Ferroelectric Polymer Langmuir-Blodgett Films"
Timothy J. Reece, Ph.D., 2007. "Characterization of Metal-Ferroelectric-Insulator-Semiconductor Structures Based on Ferroelectric Langmuir-Blodgett Polyvinyidene Fluoride Copolymer Films for Nondestructive Random Access Memory Applications"
Matt Poulsen, Ph.D., 2007. "Investigation of Ferroelectric Behavior in Electroactive Polymer Systems" Christina Othon, Ph.D. 2005. "Switching Dynamics of Ferroelectric Langmuir-Blodgett Copolymer Films"
Brad Peterson, B.S., 2004. "Pyroelectric Scanning Microscopy" Menjun Bai, Ph.D. 2002. "Structure of Ferroelectric Polymer PVDF/TrFE Copolymer Langmuir-Blodgett Films"
