New Organic Designs For Ferroelectrics

Using a newly developed computational technique to predict structural and electronic properties of as-yet-unsynthesized materials, chemists have designed a group of ferroelectric organic crystals that promise to outperform current state-of-the-art materials (J. Am. Chem. Soc. 2014, DOI: 10.1021/ja5017393). Ferroelectric materials have a knack for flipping electrical polarization when triggered by an electric field. That property makes them useful in random access memory devices, capacitors, and transistors. Common ferroelectrics such as barium titanate are inorganic. Because the range of applications could be broadened by lighter, more flexible, and less expensive materials, scientists have been searching for organic versions. Motivated by a 2012 study reporting success in synthesizing ferroelectrics based on tetrathiafulvalene (TTF), an electron donor, and pyromellitic diimide (PMDI), an electron acceptor, Shuang Chen and Xiao Cheng Zeng of the University of Nebraska, Lincoln, computationally screened tens of thousands of crystal structures based on TTF and PMDI motifs. The search turned up three highly stable compounds with predicted polarization values up to twice as large as today’s top performers.