Nanoscale Ferroelectricity in Crystalline g Glycine

Alejandro Heredia,1 Vincent Meunier,2 Igor K. Bdikin,1 José Gracio,3 Nina Balke,4 Stephen Jesse,4 Alexander Tselev,4 Pratul Agarwal,4 Bobby G. Sumpter,4 Sergei V. Kalinin4, and Andrei L. Kholkin1

1-Department of Ceramics and Glass Engineering & CICECO, University of Aveiro, 3810-193 Aveiro, Portugal
2-Physics, Astronomy and Applied Physics Department, Rensselaer Polytechnic Institute, Troy,NY 12180
3-Nanotechnology Research Div., Centre for Mechanical Technology & Automation, University of Aveiro, 3810-193 Aveiro, Portugal
4-Oak Ridge National Laboratory, Oak Ridge, TN

Achievement
Materials synthesis, experiments and computational simulations were used to produce and investigate the ferroelectric properties of g glycine. We have shown the existence of ferroelectric domains and characterized the ferroelectric switching process for different domains using piezoresponse force microscopy. Density functional theory calculations and force-field based simulations were used to explain the switching process in the glycine molecule, demonstrating molecule rotation and crystallization when electrical fields are applied locally.

Significance
Glycine is the simplest amino acid and is widely used by living organisms to build proteins. Therefore, it is a material of high significance and interest. This is the first time ferroelectric properties of g glycine have been reported. It was known to be piezoelectric since 1954, but the discovery of reversible polarization change opens new pathways to novel classes of bioelectronic logic and memory devices, where polarization switching is used to record/retrieve information in the form of ferroelectric domains.

Credit
This work was published in Advanced Functional Materials. A portion of this Research at Oak Ridge National Laboratory's Center for Nanophase Materials Sciences was sponsored by the Scientific User Facilities Division, Office of Basic Energy Sciences, U.S. Department of Energy.

“Nanoscale Ferroelectricity in Crystalline g Glycine,” A. Heredia, V. Meunier, I. K. Bdikin, J. Gracio, N. Balke, S. Jesse, A. Tselev, P. Agarwal, B. G. Sumpter, S. V. Kalinin, and A. L. Kholkin, Adv. Func. Mater. (2012); doi: 10.1002/adfm.201103011.