Zhou Lin, Li Rui-Xia, Shi Ping-Ping, Ye Qiong, Fu Da-Wei
Ordered Matter Science Research Center and Jiangsu Key Laboratory for Science and Applications of Molecular Ferroelectrics, Southeast University, Nanjing 211189, P. R. China.
College of Chemistry, Nanchang University, Nanchang 330031, P. R. China.
Inorg Chem. 2020 Dec 21;59(24):18174-18180. doi: 10.1021/acs.inorgchem.0c02649. Epub 2020 Dec 8.
Molecular phase transition compounds have become a hot research area in recent years because of their potential as functional materials, such as ferroelectrics, ferroelastics, dielectric switches, etc. However, materials combining switchable dielectric properties and ferroelasticity are still rare. Here, we reported an organic-inorganic hybrid perovskite, [CPtmp][Cd(SCN)] () ([CPtmp] is a cyclopentyltrimethylphosphonium cation), with a potential ferroelastic property. This material undergoes three structural phase transitions at 247/226, 335/312, and 349/341 K (upon heating/cooling). The successive phase transitions are mainly caused by the stepwise ordering of [CPtmp] cations and the concomitant deformation of [Cd(SCN)] anionic chains revealed by structural analyses, which triggers the double-step dielectric switching in as well. These results would inspire further exploration on molecular dielectric switches with ferroelastic properties.
近年来，分子相变化合物因其作为功能材料的潜力，如铁电体、铁弹性体、介电开关等，已成为一个热门研究领域。然而，兼具可切换介电特性和铁弹性的材料仍然很少。在此，我们报道了一种具有潜在铁弹性的有机-无机杂化钙钛矿[CPtmp][Cd(SCN)]（[CPtmp]为环戊基三甲基鏻阳离子）。该材料在247/226、335/312和349/341 K（升温/降温时）经历三次结构相变。结构分析表明，连续的相变主要是由[CPtmp]阳离子的逐步有序排列以及[Cd(SCN)]阴离子链的伴随变形引起的，这也引发了该化合物中的双步介电开关现象。这些结果将激发对具有铁弹性的分子介电开关的进一步探索。
