|Michael Sullivan Online|
Multi-Scale Modeling of Ferroelectric Polymers
Rajeev Ahluwalia, Michael B Sullivan, Jianwei Zheng, David J Srolovitz, Alfred Huan, Ping Wu, Takehisa Ishida, Kanzo Okada and Sunil M Bhangale
Contribution from Institute of Materials Research and Engineering, Institute of High Performance Computing, Yeshiva University and Sony Singapore
Presented: 2006 MRS Fall Meeting, Boston, MA United States, 27 November-1 December 2006 (2006). Symposium C: Smart Dielectric Polymer Properties, Characterization, and Their Devices.
Ferroelectric polymers are unique materials that are of interest due to their combination of good inertness, flexibility, low density and ease of fabricating. While their polarization is substantially less than the ceramic perovskites, this class of materials is still useful for certain devices.
In this work, we develop a multi-scale framework to study the polarization switching behavior in ferroelectric polymers. The model is based on theLandau-Ginzburg Devonshire (LGD) theory with the polarization as the order parameter. We incorporate the depolarization fields generated due the polarization charges at the crystalline-amorphous regions.
To make the LGD model material specific, the phenomenological parameters are obtained from atomistic molecular dynamics (MD) simulations. For example, we used MD simulations to obtain the Tc from polarization vs. temperature scans as well as related methods to obtain the alpha0 and T0. The results are compared with experimental results on PVDF-TrFe 75-25 copolymers.