The structural, dielectric, elastic, and piezoelectric properties of KNbO3 from first-principles methods
The structural, dielectric, elastic, and piezoelectric properties of KNbO3 from first-principles methods
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DOI：
10.1063/1.4712052
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发表时间：
2012-05
影响因子：
3.2
通讯作者：
L. Wan;T. Nishimatsu;S. Beckman
中科院分区：
文献类型：
--
作者：
L. Wan;T. Nishimatsu;S. Beckman
用第一性原理方法研究了KNbO 3（KNO）四种实验已知相的弹性和介电性质。沿着报道了原子结构和玻恩有效电荷张量，揭示了Nb-O键杂化与铁电结构畸变之间的关系。的介电，弹性和压电性能的每个阶段，并在文献中的结果进行比较。计算的结构被发现匹配实验的精度约为2%。虽然对单晶KNO的实验研究很少，但对正交晶系KNO的弹性参数计算值与实测值的一致性优于25%，在预期的交换相关误差范围内;然而，计算的压电系数与实验值相差多达50%，这表明，这种分歧可能不仅仅是由于理论上的近似。
The elastic and dielectric properties of the four experimentally known phases of KNbO3 (KNO) are investigated by first-principles methods. The atomic structure is reported along with the Born effective charge tensor to reveal the relation between Nb–O bonds hybridization and ferroelectric structural distortion. The dielectric, elastic, and piezoelectric properties of each phase are presented and compared to results in the literature. The computed structures are found to match experiment to an accuracy of approximately 2%. Although there have been very few experimental studies of single crystal KNO, it is found that the elastic parameters computed for orthorhombic KNO agree with the measured values to better than 25%, which is within the anticipated exchange-correlation error; however, the computed piezoelectric coefficient differ from the experimental values by as much as 50%, which suggests that the disagreement may not be solely due to the theoretical approximations.