Negative piezoelectric effect in an organic supramolecular ferroelectric

Abstract

A pronounced and tunable negative piezoelectric effect in a family of organic small-molecular ferroelectrics is demonstrated and explained.

Van der Waals layered ferroelectric CuInP2S6: Physical properties and device applications

“…Both the experimental and theoretical results confirm that such giant negative longitudinal piezoelectricity and electrostriction result from the large displacive instability of Cu ions coupled with its reduced lattice dimensionality. The proposed mechanism thus implies the prevalence of negative piezoelectricity in ferroelectrics with low-dimension lattice, as what is indeed emerging in the recent literature [89,90].…”

Multilayered Piezoelectric Nanogenerator Based on Lead-Free Poly(vinylidene fluoride)-(0.67BiFeO3-0.33BaTiO3) Electrospun Nanofiber Mats for Fast Charging of Supercapacitors

“…It can be identified from the nanoswelling formation on P40 nanofibers. Many research groups have also reported similar results. − The cause of agglomeration is due to the dispersion limit of BF33BT in PVDF solution, thus, increasing the viscosity of the solution, resulting in nanoswellings. , The average of positive peak values of V oc was found to be 11, 33, 47, 62, and 55 V for PENGs based on PVDF, P10, P20, P30, and P40, respectively (Figure c ). Similarly, the average of positive peak values of I sc was found to be 0.2, 0.6, 0.85, 0.92, and 0.88 μA in the same order (Figure d ).…”

Negative piezoelectric response of van der Waals layered bismuth tellurohalides

“…4 Negative piezoelectricity has also been experimentally demonstrated in ferroelectric polymers 5 and in organic molecular ferroelectric materials. 6 BiTeX (X = Cl, Br, and I) compounds have attracted considerable recent interest as strongly polar quasi-2D materials. The breaking of inversion symmetry results from the layer geometry, in which a central Bi layer is neighbored by a Te layer on one side and a halide layer on the other side, forming a triple layer (TL) as shown in Fig.…”