The project aims at studying and improving some classes of organic and metal-organic piezoelectric materials (in which a stress causes an electric field and vice versa), which recently come into the limelight due to their unexpectedly high electromechanical coupling constants. This promises great progress for applications where economical, flexible, light and eco-compatible piezoelectrics are needed.
The project is focused on two types of materials: (1) the [TMFM]_x[TMCM]_(1-x)CdCl₃ [TM(F/C)M = trimethyl(fluoro/chloro)methyl ammonium] solid solution, which has been shown to have a piezoelectric coefficient d33 = 1500 pC/N, much higher than classic ceramic  PZT; (2) organic perovskites of the [MDABCO][NH₄]I₃ type (MDABCO = C₇N2H₁₆). The latter presently have a maximum d33 = 14 pC/N, like polymer ferroelectrics, but they are cubic in the paraelectric phase, implying that the spontaneous polarization may reorient in any direction, at variance with (1) and ferroelectric polymers. The fact that the direction of the polarization is not restricted by the cell structure gives hope that it would be possible to obtain good piezoelectric properties by increasing the molecular dipole moments and their coupling.

Thematic Area:Energia
Financin body:CNR
Starting year:2020
End year:2022
Call:Progetto bilaterale CNR-Accademia delle Scienze di Romania
Title:Piezoelectric and Multiferroic Molecular Perovskites for Flexible and Wearable Devices
Budget ISM (k€):4
Role ISM:Unit Coordinator
Referent ISM:Francesco Cordero
Other ISM staff envolved:Floriana Craciun, Anna Maria Paoletti, Gloria Zanotti
Laboratory: Lab-AnelSpec, Lab-DielSpec, Syn-o-Mat