Ferroelectric mechanism of croconic acid: a first-principles and Monte Carlo study.
Ferroelectric mechanism of croconic acid: a first-principles and Monte Carlo study.
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DOI：
10.1063/1.4813500
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发表时间：
2013-07
期刊：
影响因子：
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通讯作者：
Yaxuan Cai;S. Luo;Zhanwu Zhu;H. Gu
中科院分区：
文献类型：
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作者：
Yaxuan Cai;S. Luo;Zhanwu Zhu;H. Gu
采用密度泛函理论和广义梯度近似方法，从电子结构和分子结构两方面研究了克酮酸的铁电机理.用Berry相位法模拟了自发极化（Ps）。研究发现，这种大的极化是由于放电子基团和吸电子基团沿氢键的强“推拉”效应引起的电荷转移所致。根据克糖酸的极化特性，建立了一维铁电哈密顿模型来描述克糖酸的铁电性质。基于哈密顿模型，采用蒙特卡罗方法研究了克糖酸铁电性的热性质。模拟的居里温度为756 K，自发极化在400 K以内保持良好的温区稳定性。这些结果与实验数据符合得很好。
The ferroelectric mechanism of croconic acid in terms of the electronic structure and the molecular structure was studied by first principles using the density functional theory with the generalized gradient approximation. The spontaneous polarization (Ps) was simulated by the Berry phase method. It is found that the large polarization originates from charge transfer due to the strong "push-pull" effect of electron-releasing and -withdrawing groups along the hydrogen bond. According to the characteristics of polarization of croconic acid, we constructed a one-dimensional ferroelectric Hamiltonian model to describe the ferroelectric properties of croconic acid. Based on the Hamiltonian model, the thermal properties of the ferroelectricity of croconic acid were studied by Monte Carlo method. The simulated Curie temperature is 756 K, and the spontaneous polarization keeps well temperature range stability up to 400 K. These results are in good agreement with the experimental data.