Synthesis and Characterization of a Displacement-Type Ferroelectric–Ferroelectric Phase Transition Compound [(NH₃)(CH₂)₃(NH₃)]₂[InBr₆]Br·H₂O

Abstract

Ferroelectric materials have aroused the researchers' great interest due to their wide applications. Here, a displacement-type ferroelectric−ferroelectric phase transition material [(NH 3 )(CH 2 ) 3 (NH 3 )] 2 [InBr 6 ]Br•H 2 O (1) with T c = 143 K was successfully prepared. The ferroelectric phase transition is verified by the characterization techniques such as differential scanning calorimetry, single-crystal structure elucidation, dielectric and ferroelectric measurements. The single-crystal structure elucidation reveals that the displacement and distortion of [(NH 3 )(CH 2 ) 3 (NH 3 )] 2+ cations lead to the phase transition from Cmc2 1 to Pca2 1 . The spontaneous polarizations at 293 and 133 K are 0.15 and 0.12 μC•cm −2 , respectively. We expect that this work will help in further exploration of some new ferroelectric materials.

High-Tc Fe-based ferroelectric compound with large spontaneous polarization and narrow bandgap

“…2a, it can be observed that the distance between the propyl groups in the red dashed circle is significantly greater than that in 1-HTP , indicating that compound 1 undergoes a second-order shift phase transition. Based on the structural analysis of 1-LTP and 1-HTP , we can conclude that compound 1 undergoes a second-order shift ferroelectric–ferroelectric phase transition at 390 K, similar to the situation of [(NH 3 )(CH 2 ) 3 (NH 3 )] 2 [InBr 6 ]Br·H 2 O 39 and a pair of enantiomorphic diarylethene derivative ferroelectric crystals reported by Tang. 33…”

Two In-based Hybrid Compounds with Structural Phase Transitions Caused by Displacement Motion or Dynamic Disorder

“…Crystal structure analyses prove that the disorder–order change of the tetraalkylammonium cation induces phase transitions . In our previous work, we have found some inorganic–organic hybrid compounds with disorder–order or displacive phase transitions in the A n –3 [In III X n ] system. − For instance, (C 4 H 10 N) 6 [InBr 6 ]­[InBr 4 ] 3 ·H 2 O exhibits a couple of thermal anomaly peaks at 232/227 K. The key factor for the phase transition is the disorder–order behavior of [InBr 4 ] − cations . Afterward, the displacement-type material [(NH 3 )­(CH 2 ) 3 (NH 3 )] 2 [InBr 6 ]­Br·H 2 O ( T p = 143 K) shows a ferroelectric–ferroelectric phase transition.…”

“…Afterward, the displacement-type material [(NH 3 )­(CH 2 ) 3 (NH 3 )] 2 [InBr 6 ]­Br·H 2 O ( T p = 143 K) shows a ferroelectric–ferroelectric phase transition. The displacive motion of organic cations provides the driving force for the phase transition . The studies described above indicate that A n –3 [In III X n ] offers an appropriate platform for the research of phase transition materials.…”