Abstract
Molecular ferroelectrics have attracted much attention because of their excellent piezoelectricity,me-chanical workability,and second harmonic effect.Here,we successfully prepared two molecular fer-roelectrics[1,5-3.2.2-Hdabcn]X(X=ClO4-,1;ReO4-,2)by reactions of a quasi-spherical amine 1,5-diazabicycle[3.2.2]nonane(1.5-3.2.2-dabcn)with HX aqueous solution.Compounds 1 and 2 undergo high-temperature phase transitions at 381K(1)and 396K(2).Before and after the phase transition,they crystallize in the polar point group mm2,and the centrosymmetric point groups mmm and 4/mmm,re-spectively.According to Aizu rules,these two compounds experience mmmFmm2 and 4/mmmFmm2 type ferroelectric phase transitions,respectively.The ferroelectricity of both compounds is well expressed in their polycrystalline film at room temperature with low coercive voltages of 13 V for 1 and 25 V for 2.Us-ing piezoelectric force microscopy(PFM),the 180° anti-parallel ferroelectric domains and the reversible polarization switching can be clearly observed in 1 and 2.This high-temperature molecular ferroelec-tric material has great application potential in flexible materials,biomechanics,intelligent wearables and other fields.
基金项目
National Natural Science Foundation of China(21865015)
National Natural Science Foundation of China(22071094)
National Natural Science Foundation of China(22075123)
Department of Science and Technology in Jiangxi Province(20213BCJ22055)
NETL
NSTL
万方数据