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Hairui Xia Jiyang Wang Lixia Li Zhigiang Zou 《Progress in Crystal Growth and Characterization of Materials》2000,40(1-4):253-261
A new series of non-ferroelectric crystals, the piezoelectric solid solution aluminium gallium orthophosphate Al1-xGaxPO4 (AGP, 0 < x < 1) system has been successfully developed by a hydrothermal method. The AGP crystal with X = 0.10 shows a phase transition temperature T−β = 587 ± 3 °C with a cell parameters A = b = 0.49386(3) and C = 1.09563(2) nm. Raman spectra including directional dispersion in AGP are similar to those from -AIPO4 and -quartz crystals, indicating all of them belong to an isomorphic family, the short-range interaction being dominant in AGP. Comparison with -AIPO4 crystals, there exists an apparent red shift of the mode frequency and a smaller TO/LO mode splitting of the E species in the AGP crystals. 相似文献
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Feng Cheng Shuqi Wu Wenwei Zheng Shengqun Su Takumi Nakanishi Wenhuang Xu Pritam Sadhukhan Hibiki Sejima Shimon Ikenaga Kaoru Yamamoto Kaige Gao Shinji Kanegawa Prof. Osamu Sato 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(59):e202202161
The crystallization of a complex having electron transfer properties in a polar space group can induce the polarization switching of a crystal in a specific direction, which is attractive for the development of sensors, memory devices, and capacitors. Unfortunately, the probability of crystallization in a polar space group is usually low. Noticing that enantiopure compounds crystallize in Sohncke space groups, this paper reports a strategy for the molecular design of non-ferroelectric polarization switching crystals based on the use of intramolecular electron transfer and chirality. In addition, this paper describes the synthesis of a mononuclear valence tautomeric (VT) cobalt complex bearing an enantiopure ligand. The introduction of enantiomer enables the crystallization of the complex in the polar space group (P21). The polarization of the crystals along the b-axis direction is not canceled out and the VT transition is accompanied by a change in the macroscopic polarization of the polar crystal. Polarization switching via electron transfer is realized at around room temperature. 相似文献
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Yao‐Zu Zhang Dong‐Sheng Sun Ji‐Xing Gao Xiu‐Ni Hua Xiao‐Gang Chen Guang‐Quan Mei Wei‐Qiang Liao 《化学:亚洲杂志》2019,14(7):1028-1033
Piezoelectric materials are a class of important functional materials applied in high‐voltage sources, sensors, vibration reducers, actuators, motors, and so on. Herein, [(CH3)3S]3[Bi2Br9]( 1 ) is a brilliant semiconducting organic–inorganic hybrid perovskite‐type non‐ferroelectric piezoelectric with excellent piezoelectricity. Strikingly, the value of the piezoelectric coefficient d33 is estimated as ≈18 pC N?1. Such a large piezoelectric coefficient in non‐ferroelectric piezoelectric has been scarcely reported and is comparable with those of typically one‐composition non‐ferroelectric piezoelectrics such as ZnO (3pC N?1) and much greater than those of most known typical materials. In addition, 1 exhibits semiconducting behavior with an optical band gap of ≈2.58 eV that is lower than the reported value of 3.37 eV for ZnO. This discovery opens a new avenue to exploit molecular non‐ferroelectric piezoelectric and should stimulate further exploration of non‐ferroelectric piezoelectric due to their high stability and low loss characteristics. 相似文献
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采用传统陶瓷烧结工艺成功制备出新型非铁电压电复合陶瓷SrTiO3-Bi12TiO20(ST-BT),利用正电子湮没技术,对ST-BT复合陶瓷烧结过程进行了研究,讨论了烧结过程中材料内部的缺陷变化特征,给出了烧结温度对该复合陶瓷结晶度和缺陷结构的影响.发现烧结温度在860—940℃,烧结时间为3 h的实验条件下,ST-BT复合陶瓷已趋于稳定,出现了大量的单空位型缺陷.烧结温度超过980℃将引起Bi12TiO20相的大量分解,杂相的出现造成缺陷的聚集,形成大尺度的微空洞.实验结果表明,烧结温度在920—940℃的烧结条件下,ST-BT复合陶瓷的结构特性及压电性能均表现出较好的稳定性. 相似文献
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