Multiaxial Molecular Ferroelectrics with a Large Viable Temperature Range

Molecular ferroelectrics, due to their structural diversity, tunability, and ease of handling, have received widespread attention, which are viable alternatives or supplements to traditional ceramic ferroelectrics, and are expected to solve increasingly serious energy and environmental problems. However, low Tc limits the application of molecular ferroelectrics. We break the highly symmetrical structure of the spherical molecule dabco, introducing n-butyl groups and combining modified cations with several cobalt halides. The resulting compound [n-Budabco]CoBr3 (n-Budabco = N-n-butyl-N′-diazabicyclo[2,2,2]octane) crystallized in a polar point group (mm2), and no phase transition behavior was obtained before decomposing (603 K). The ferroelectricity was adequately verified by P–E hysteresis loop and ferroelectric domain observation. To the best of our knowledge, such a wide viable temperature range is unprecedented among the reported molecular ferroelectrics. This work will not only enrich high-temperature ferroelectrics but also inspire more creative optimization strategies of ferroelectricity.