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Articles 1 - 5 of 5
Full-Text Articles in Materials Science and Engineering
Modeling Of Metal-Ferroelectric-Insulator-Semiconductor Structures Based On Langmuir–Blodgett Copolymer Films, Timothy J. Reece, Stephen Ducharme
Modeling Of Metal-Ferroelectric-Insulator-Semiconductor Structures Based On Langmuir–Blodgett Copolymer Films, Timothy J. Reece, Stephen Ducharme
Stephen Ducharme Publications
Among the ferroelectric thin films used in field-effect transistor devices; the ferroelectric copolymer of polyvinylidene fluoride PVDF –CH2–CF2–, with trifluoroethylene TrFE –CHF–CF2–, has distinct advantages, including low dielectric constant, low processing temperature, low cost, and compatibility with organic semiconductors. The operation of a metal-ferroelectric insulatorsemiconductor structure with PVDF-TrFE as the ferroelectric layer was analyzed and optimized by numerical solution of the Miller and McWhorter model. A model device consisting of 20 nm PVDF/TrFE on a 10-nm-thick high-k dielectric buffer exhibits a memory window of 5 V with an operating voltage of 15 V. The operating voltage can be reduced to …
Nanoscale Domain Patterns In Ultrathin Polymer Ferroelectric Films, Pankaj Sharma, Timothy J. Reece, Daniel W. Wu, Vladimir M. Fridkin, Stephen Ducharme, Alexei Gruverman
Nanoscale Domain Patterns In Ultrathin Polymer Ferroelectric Films, Pankaj Sharma, Timothy J. Reece, Daniel W. Wu, Vladimir M. Fridkin, Stephen Ducharme, Alexei Gruverman
Stephen Ducharme Publications
High-resolution studies of domain configurations in Langmuir–Blodgett films of ferroelectric polymer poly(vinylidene fluoride-trifluoroethylene), P(VDF-TrFE), have been carried out by means of piezoresponse force microscopy (PFM). Changes in film thickness and morphology cause significant variations in polarization patterns. In continuous films and nanomesas with relatively low thickness/grain aspect ratio (<1/10), the relationship between the average domain size and thickness follows the Kittel law. Nanomesas with high aspect ratio (>1/5) exhibit significant deviations from this law, suggesting additional surface-energy-related mechanisms affecting the domain patterns. Polarization reversal within a single crystallite has been demonstrated and local switching parameters (coercive voltage and remnant piezoresponse) have been measured by monitoring the local hysteresis loops. Reliable control of polarization at the sub-grain level demonstrates …
Dielectric Nanocomposites: An Inside-Out Approach To Storing Electrostatic Energy, Stephen Ducharme
Dielectric Nanocomposites: An Inside-Out Approach To Storing Electrostatic Energy, Stephen Ducharme
Stephen Ducharme Publications
The ability to achieve high-energy densities is the central challenge in energy storage and recovery. A promising strategy for increasing energy storage is to use highperformance dielectric materials, such as highly polarizable nanoparticles or polymers, or nanocomposites of the two. In this issue, Kim et al. use a molecular coating and clever chemistry to combine oxide nanoparticles with a polymer matrix, thereby producing an improved nanocomposite dielectric. Some advantages and challenges of using nanocomposites as improved dielectric materials are presented in this Perspective.
Polarization Switching Kinetics Of Ferroelectric Nanomesas Of Vinylidene Fluoride-Trifluoroethylene Copolymer, R. V. Gaynutdinov, O. A. Lysova, S. G. Yudin, A. L. Tolstikhina, A. L. Kholkin, V. M. Fridkin, Stephen Ducharme
Polarization Switching Kinetics Of Ferroelectric Nanomesas Of Vinylidene Fluoride-Trifluoroethylene Copolymer, R. V. Gaynutdinov, O. A. Lysova, S. G. Yudin, A. L. Tolstikhina, A. L. Kholkin, V. M. Fridkin, Stephen Ducharme
Stephen Ducharme Publications
The polarization switching kinetics of ferroelectric polymer nanomesas was investigated using piezoresponse force microscopy. The nanomesas were made by self-organization from Langmuir–Blodgett films of a 70% vinylidene fluoride and 30% trifluoroethylene copolymer. The polarization switching time exhibits an exponential dependence on reciprocal voltage that is consistent with nucleation-type switching dynamics.
Polymer Composite And Nanocomposite Dielectric Materials For Pulse Power Energy Storage, P. Barber, S. Balasubramanian, Y. Anguchamy, S. Gong, A. Wibowo, H. Gao, Harry J. Ploehn, Hans-Conrad Zur Loye
Polymer Composite And Nanocomposite Dielectric Materials For Pulse Power Energy Storage, P. Barber, S. Balasubramanian, Y. Anguchamy, S. Gong, A. Wibowo, H. Gao, Harry J. Ploehn, Hans-Conrad Zur Loye
Faculty Publications
This review summarizes the current state of polymer composites used as dielectric materials for energy storage. The particular focus is on materials: polymers serving as the matrix, inorganic fillers used to increase the effective dielectric constant, and various recent investigations of functionalization of metal oxide fillers to improve compatibility with polymers. We review the recent literature focused on the dielectric characterization of composites, specifically the measurement of dielectric permittivity and breakdown field strength. Special attention is given to the analysis of the energy density of polymer composite materials and how the functionalization of the inorganic filler affects the energy density …