title: A Molecular Perovskite with Switchable Coordination Bonds for High-Temperature Multiaxial Ferroelectrics.
abstract: The underlying phase transitions of ferroelectric mechanisms in molecular crystals are mainly limited to order-disorder and displacive types that are not involved in breaking of the chemical bonds. Here, we show that the bond-switching transition under ambient pressure is designable in molecular crystals, and demonstrate how to utilize the weaker and switchable coordination bonds in a novel molecular perovskite, [(CH3)3NOH]2[KFe(CN)6] (TMC-1), to afford a scarce multiaxial ferroelectrics with a high Curie temperature of 402 K and 24 equivalent ferroelectric directions (more than BaTiO3). The high-quality thin films of TMC-1 can be easily fabricated by a simple solution process, and to reveal perfect ferroelectric properties at both macroscopic and microscopic scales, suggesting TMC-1 as a promising candidate for applications in next-generation flexible electronics. The presented molecular assembly strategy, together with the achieved bond-switching ferroelectric mechanism, opens a new avenue for designing advanced ferroelectric materials.
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, China.
authors.forename: Wei-Jian
authors.initials: WJ
authors.lastname: Xu
authors.affiliation: Ordered Matter Science Research Center, Southeast University , Nanjing 211189, China.
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Li
authors.affiliation: Ordered Matter Science Research Center, Southeast University , Nanjing 211189, China.
authors.forename: Yuan-Yuan
authors.initials: YY
authors.lastname: Tang
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, China.
authors.forename: Wei-Xiong
authors.identifier: 0000-0003-0797-3465
authors.initials: WX
authors.lastname: Zhang
authors.affiliation: Ordered Matter Science Research Center, Southeast University , Nanjing 211189, China.
authors.forename: Ren-Gen
authors.identifier: 0000-0003-2364-0193
authors.initials: RG
authors.lastname: Xiong
authors.affiliation: MOE Key Laboratory of Bioinorganic and Synthetic Chemistry, School of Chemistry, Sun Yat-Sen University , Guangzhou 510275, China.
authors.forename: Xiao-Ming
authors.identifier: 0000-0002-3353-7918
authors.initials: XM
authors.lastname: Chen