Polarized ferroelectric crystal material
Ferroelectrics are an important class of polar optoelectronic functional materials, exhibiting a wealth of nonlinear optics, piezoelectric, pyroelectric, ferroelectric and photovoltaic properties. The essential feature is that spontaneous polarization reverses under the action of an external electric field. In recent years, ferroelectric molecular compounds have received extensive attention and gradually developed into an important supplementary material for traditional inorganic ferroelectric ceramics. However, how to achieve rapid reversal of spontaneous polarization is the current needs of molecular ferroelectric materials research institutes. An important issue to solve.
The State Key Laboratory of Structural Chemistry of the Institute of Physical Structures, Chinese Academy of Sciences, 'Inorganic Photoelectric Functional Crystal Materials' Researcher Luo Junhua's National Natural Science Foundation, hosted by the National Outstanding Youth Fund, the Strategic Pilot Program of the Chinese Academy of Sciences and Sun Zhihua, a researcher at the Haixi Research Institute 'Team 100 People' Under the auspices of the Excellent Youth Fund of the Fund Committee and the Outstanding Youth Fund of Fujian Province, an ion-type ferroelectric compound was designed and synthesized and a rapid reversal of the spontaneous polarization effect was achieved. The study found that: N-methylmorpholine cations in the compound *** Anions are connected by a strong NH...O hydrogen bond, and the two structural elements undergo an order-disorder change at a temperature of around 315 K, synergistically inducing the spontaneous polarization effect of the compound; Further, the ferroelectric phase transition process of the compound was confirmed by second-order nonlinear optical effects, pyroelectricity, hysteresis loop and variable temperature solid-state magnetic spectroscopy. In addition, the spontaneous polarization of the material was applied by an applied electric field. Very easy to reverse, flipping up to a record 263 KHz. This work not only achieves ferroelectric molecular compounds It also provides potential for further expansion of the application of this type of material; the relevant research results were recently published in the form of communication in German Applied Chemistry (Angew. Chem., Int. Ed., 2018, doi:org/ 10.1002/ange.201805776) Above. Due to the originality, novelty and importance of the work, the paper was highly praised by reviewers and was selected as the magazine's VIP (Very Important Paper) article. Sun Zhihua is the paper. The first author.
Recently, the team has made a series of advances in the design and synthesis of ferroelectric crystal materials and the photoelectric properties of related materials (J. Am. Chem. Soc., 2018, 140, 6806–6809; Angew. Chem., Int. Ed. , 2018, doi:org/10.1002/ange.201805776; Angew. Chem., Int. Ed., 2018, doi:org/10.1002/ange.201803716; Adv. Funct. Mater., 2018, 28, 1705467; Laser Photonics Rev., 2018, doi.10.1002/lpor.201800060).
