An Above‐Room‐Temperature Phase Transition with Dielectric‐Switching Properties in a Halogenobismuthate(III) – Tris(Cyclohexylmethylammonium) Pentabromobismuthate(III) Bromide. Issue 29 (10th August 2017)

• Record Type: Journal Article
• Authors: Yin, Zi; Gao, Ji‐Xing; Chen, Hai‐Peng; Liao, Wei‐Qiang
• Is Part Of: European journal of inorganic chemistry. Issue 29(2017)
• Page Start: 3555
• Page End: 3560
• Publication Date: 2017-08-10
• Subjects: Phase transitions -- Bismuth -- Dielectric properties -- Structure elucidation; Chemistry, Inorganic -- Periodicals; Organometallic chemistry -- Periodicals; Bioinorganic chemistry -- Periodicals; Solid state chemistry -- Periodicals; 546
• DOI: 10.1002/ejic.201700529
• Languages: English
• ISSNs: 1434-1948

Abstract

Abstract : A one‐dimensional halogenobismuthate(III), [CMA]3 · [BiBr5 ]· [Br] (1, CMA = cyclohexylmethylammonium), is discovered as a high‐temperature phase‐transition material with reversible and switchable dielectric behavior. Compound1 undergoes a solid‐state phase transition at T C = 401.6 K, as confirmed by differential scanning calorimetry (DSC), variable‐temperature single‐crystal X‐ray diffraction, variable‐temperature powder X‐ray diffraction (PXRD), and dielectric measurements. Compound1 crystalizes in the monoclinic space group P 21 / c in the room‐temperature phase (RTP). The asymmetric unit of1 consists of three independent CMA cations, one isolated Br – anion, and one [BiBr5 ] 2– anion, which extends along the c axis to form a one‐dimensional zigzag chain through corner‐sharing BiBr6 octahedra. Interestingly, the temperature‐dependent dielectric constants display striking steplike dielectric anomalies with two distinct dielectric states below and above T C ; therefore, 1 could be conceived to be an appealing candidate for dielectric switches. It is believed that this finding might pave the way to the exploration and design of high‐temperature phase‐transition materials for practical applications. Abstract : A one‐dimensional organic–inorganic hybrid halogenobismuthate(III) compound, tris(cyclohexylmethylammonium) pentabromobismuthate(III) bromide, exhibits a reversible first‐order structural phase transition at high temperature (401.6 K) that is accompanied by switchable dielectric behavior between low and high dielectric states.