Organic‐inorganic Hybrid ([BrCH₂CH₂N(CH₃)₃]⁺₂[CdBr₄]²⁻) with Unusual Ferroelectric and Switchable Dielectric Bifunctional Properties over Different Temperature Range

Abstract

Both ferroelectric and switchable dielectric behaviors are of great academic value and practical significance, but they usually exist alone. If combine the two properties into one compound, it will be more valuable in practical application. In this paper, quasi-spherical (2-bromoethyl) trimethylammonium cation was used to match with [CdBr 4 ] 2À anion, and a new organic-inorganic hybrid compound ([BrCH 2 CH 2 N(CH 3 ) 3 ] + 2 [CdBr 4 ] 2À , BETABCdBr) was obtained and carefully characterized. The results indicate that this compound undergoes two continuous reversible phase transition around 342 K and 390 K. It could respectively exhibit ferroelectric and switchable dielectric properties over different temperature range. This work may provide a new clue to explore new types of bifunctional phase transition smart materials to meet various application requirements.

Singlet exciton and singlet/triplet self-trapped excitons for ultra-broadband white-light emission in a zero-dimensional cadmium bromide hybrid

“…The large band gap is similar to those of the previously reported cadmium-based materials. 50–53 Furthermore, we performed the first-principles DFT calculations for the title compound (for details in the ESI†). The calculated band structure in Fig.…”

A multifunctional molecular ferroelectric with chiral features, a high Curie temperature, large spontaneous polarization and photoluminescence: (C9H14N)2CdBr4

“…6d ), the direct band gap value of compound 1 is 4.24 eV. Compared with the organic–inorganic hybrid metal halide ferroelectric ([BrCH 2 CH 2 N(CH 3 ) 3 ] 2 + [CdBr 4 ] 2− ) ( E g = 4.96 eV) containing the same inorganic anion [CdBr 4 ] 2− , 22 the band gap value is smaller, and it is less than that of [C 3 H 5 NH 3 ] 2 CdCl 4 ( E g = 5.20 eV). 49 In order to further understand the semiconductor properties of compound 1 , we calculated its band structure and PDOS.…”

“…Therefore, lead-free Bi-based and Cd-based hybrid metal halides are considered to be the most promising substitutes due to their low toxicity and high stability. 20 There are only a few multifunctional organic–inorganic metal halide ferroelectrics containing the inorganic anion CdBr 4 2− in the literature, such as (3-pyrrolinium)CdBr 3 ( T c = 260 K), 21 ([BrCH 2 CH 2 N(CH 3 ) 3 ] 2 + [CdBr 4 ] 2− ) ( T c = 390 K), 22 [cyclopentylammonium] 2 CdBr 4 ( T c = 340 K), 23 (diisopropylammonium) 2 [CdBr 4 ] ( T c = 244 K), 24 [BnNMe 2 R]CdBr 4 ( T c = 400 K), 25 and Cd-based molecular ferroelectrics with both chiral and luminescent properties are rare.…”

Bromination of organic spacer impacts on the structural arrangement, phase transitions, and optical and electrical properties of a hybrid halide compound:[(CH3)3N(CH2)3Br]2PdBr4

“…Currently, a novel family of hybrid ferroelectric compounds has emerged through the selective bromination of the alkylammonium salts into hybrid metal–halide materials. 33–35 A spherical tetramethylammonium cation has been subject to modification by substituting one of its hydrogen atoms with a CH 2 Br group. This innovation has led to the creation of innovative hybrid halide compounds, namely [Br(CH 2 ) 2 N(CH 3 ) 3 ] 2 CuBr 4 34 and [Br(CH 2 ) 2 N(CH 3 ) 3 ] 2 CdBr 4 , 35 in which the (2-bromoethyl)trimethylammonium cation occupies the space enclosed by the [CuBr 4 ] 2− or [CdBr 4 ] 2− anions.…”