Bis(imidazolium) L‐Tartrate: A Hydrogen‐Bonded Displacive‐Type Molecular Ferroelectric Material

Abstract

Ein H‐Brücken‐gebundener ionischer Cokristall mit Imidazol als molekularem Rotator und L‐Weinsäure als homochiraler Komponente erweist sich als displazives ferroelektrisches Material, das bei 252 K eine Phasenumwandlung von paraelektrisch nach ferroelektrisch durchläuft (siehe Bild). Das außergewöhnliche dielektrische Verhalten wird durch Atomverschiebungen ausgelöst.

A High‐Temperature Molecular Ferroelectric Zn/Dy Complex Exhibiting Single‐Ion‐Magnet Behavior and Lanthanide Luminescence

“…Molecular ferroelectrics are an alternative and emerging class of ferroelectrics, because they exhibit flexible molecular structures, optical transparency, low density, tunable physical and chemical properties and are synthesized using soft chemistry routes. The resulting molecular systems can exhibit electrical bistability above room temperature, making them competitive with perovskite type materials, as recently demonstrated for organo-ferroelectric materials based on croconic acid, [12] functionalized benzimidazoles, [13] bis(imadazolium)-l-tartrate, [14] and diisopropylammonium bromide. [15] Ferroelectric properties require the absence of an inversion center in the crystal structure that consequently gives rise to additional functionalities, such as non-linear optical properties or piezoelectricity.…”

A Molecular Ferroelectric Thin Film of Imidazolium Perchlorate That Shows Superior Electromechanical Coupling

“…electrics that are lightweight, [6] mechanically flexible, and environmentally friendly, with their ferroelectric properties approaching those of perovskites. [7] For example, croconic acid was shown to possess a high spontaneous polarization of around 23 mC cm À2 , [8] which is comparable to that of BTO, while diisopropylammonium bromide (DIPAB) was found to have a high ferroelectric phase transition temperature of 426 K, exceeding that of BTO as well as new ferroelectric physics, [9] such as charge-transfer along p···p-stacked supramolecular networks of electron donors and acceptors leading to spontaneous polarization.…”

Crystal Structure and Phase Transition of the C–H···F–H-Bonded Supramolecular Compound with 4-Nitroanilinium Based on 18-Crown-6

“…Various components of phase-transition materials have been investigated, including metal-organic, pure inorganic, organic hydrogen-bonded, and organic-inorganic hybrid materials. Among them, inorganic-organic hybrid complexes exhibit fascinating structures or prominent functionalities because of their hybrid inorganic-organic advantages [5][6][7][8][9]. The crystalline materials of inorganic-organic hybrid compounds with phase-transition or peculiar molecular packing modes display remarkable and unusual dielectric properties, ferroelectric transfer, superconductivity, and magnetic coupling [10][11][12][13].…”