Hydrogen-bonded single-component organic ferroelectrics revisited by van der Waals density-functional theory calculations
Hydrogen-bonded single-component organic ferroelectrics revisited by van der Waals density-functional theory calculations
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DOI：
10.1103/physrevmaterials.5.094409
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发表时间：
2021-09-22
影响因子：
3.4
通讯作者：
Kumai, Reiji
中科院分区：
文献类型：
--
作者：
Ishibashi, Shoji;Horiuchi, Sachio;Kumai, Reiji
采用货车德瓦耳斯密度泛函理论（vdw-DFT）计算了7种氢键单组分有机铁电体的晶体结构参数和自发极化值。计算结果与实验结果吻合较好，为有机铁电材料的计算设计迈出了重要的一步。这种方法还能够模拟机电响应。用vdW-DFT方法计算了单轴应力或电场作用下的克康酸（CRCA）、2-苯基丙二醛（PhMDA）和5，6-二氯-2-甲基苯并咪唑（DC-MBI）。直接压电d（33）常数由作为应力的函数的极化变化来计算，而匡威压电d（33）常数由作为电场的函数的晶格参数的变化来计算。如果考虑可能的客观因素，所得到的值与实验值显示出可接受的协议。应力引起的或电场引起的极化的变化进行了分析，考虑两种类型的贡献。一个是质子转移作为一个经典的点电荷运动，另一个剩余部分对应于π电子的重新分布。
We apply van der Waals density-functional theory (vdW-DFT) calculations to predict crystal structure parameters and spontaneous polarization values for seven hydrogen-bonded single-component organic ferroelectrics. The results show good agreement with experimental results, implying that an important step for the computational materials design of organic ferroelectrics has been achieved. This approach also enables the simulation of electromechanical responses. Calculations using the vdW-DFT method are performed for croconic acid (CRCA), 2-phenylmalondialdehyde (PhMDA), and 5,6-dichloro-2-methylbenzimidazole (DC-MBI) under uniaxial stresses or electric fields. Direct piezoelectric d(33) constants are evaluated from the polarization change as a function of stress, whereas converse piezoelectric d(33) constants are evaluated from the change in lattice parameter as a function of electric field. The obtained values show acceptable agreement with the experimental values if possible objective factors are considered. The stress-induced or electric-field-induced variation of polarization is analyzed considering two types of contributions. One is from proton transfer as a classical point charge motion and the other residual part corresponds to the redistribution of pi electrons.