A High Working Temperature Multiferroic Induced by Inverse Temperature Symmetry Breaking

作者：Lei-Yu Zhan, Yu Zhou, Na Li, Linjie Zhang, Xiao‐Juan Xi, Zhao‐Quan Yao, Jiong‐Peng Zhao, Xian‐He Bu · 发表于：Journal of the American Chemical Society · 年份：2024 · DOI：10.1021/jacs.3c12842 · 被引用次数：34 · 研究领域：Polyoxometalates: Synthesis and Applications、Nonlinear Optical Materials Research、Solid-state spectroscopy and crystallography

Molecular-based multiferroic materials that possess ferroelectric and ferroelastic orders simultaneously have attracted tremendous attention for their potential applications in multiple-state memory devices, molecular switches, and information storage systems. However, it is still a great challenge to effectively construct novel molecular-based multiferroic materials with multifunctionalities. Generally, the structure of these materials possess high symmetry at high temperatures, while processing an obvious order–disorder or displacement-type ferroelastic or ferroelectric phase transition triggered by symmetry breaking during the cooling processes. Therefore, these materials can only function below the Curie temperature ( T c ), the low of which is a severe impediment to their practical application. Despite great efforts to elevate T c, designing single-phase crystalline materials that exhibit multiferroic orders above room temperature remains a challenge. Here, an inverse temperature symmetry-breaking phenomenon was achieved in [FPM][Fe 3 (μ 3 -O)(μ-O 2 CH) 8 ] (FPM stands for 3-(3-formylamino-propyl)-3,4,5,6-tetrahydropyrimidin-1-ium, which acts as the counterions and the rotor component in the network), enabling a ferroelastoelectric phase at a temperature higher than T c (365 K). Upon heating from room temperature, two-step distinct symmetry breaking with the mm2 F m species leads to the coexistence of ferroelasticity and ferroelectricity in the temperature interval of 36...