Huang Yuan, Yang Jie, Li Zi-Jian, Qian Kun, Sao Feng
College of Pharmacy, Jiangxi University of Traditional Chinese Medicine Nanchang 330004 P. R. China
Shanghai Institute of Applied Physics, Chinese Academy of Sciences Shanghai 201800 P. R. China
RSC Adv. 2019 Apr 2;9(18):10364-10370. doi: 10.1039/c9ra00804g. eCollection 2019 Mar 28.
A new lead-bromide hybrid organic-inorganic complex [EtN][PbBr] (Et = ethyl) was synthesized, and its crystal structures could be described as a distorted perovskite-like one (at room temperature phase and at high temperature phase) and a step-like dielectric anomaly was obtained at around 375 K upon heating and 367 K upon cooling. It underwent a reversible structural phase transition with the Aizu notation of 6/2/ belonging to one of the 94 species of ferroelastic phase transitions, displayed switchable dielectric behaviors triggered by the motion or reorientation of the tetraethylammonium cations and the displacement of Pb and Br ions in a solid-state crystal. Ferroelastic domain walls were also observed in atomic-force microscopy. Differential scanning calorimetry, dielectric measurements and variable-temperature X-ray structure determinations indicated this complex exhibited a dielectric anomaly associated with the structural phase transition. All of these demonstrate its potential application as a temperature switchable molecular dielectric material in the ferroic-related field.
合成了一种新型的溴化铅杂化有机-无机配合物[EtN][PbBr]（Et = 乙基），其晶体结构在室温相和高温相可描述为类似畸变钙钛矿结构，加热时在约375 K、冷却时在约367 K出现阶梯状介电异常。它经历了具有Aizu符号6/2/的可逆结构相变，属于94种铁弹性相变之一，在固态晶体中由四乙铵阳离子的运动或重取向以及Pb和Br离子的位移触发可切换介电行为。在原子力显微镜中也观察到了铁弹性畴壁。差示扫描量热法、介电测量和变温X射线结构测定表明该配合物表现出与结构相变相关的介电异常。所有这些都证明了其作为铁性相关领域中温度可切换分子介电材料的潜在应用。
