Atomistic origin of the inverse piezoelectric effect in α-SiO2 and α-GaPO4
Atomistic origin of the inverse piezoelectric effect in α-SiO2 and α-GaPO4
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α-SiO2 和 α-GaPO4 中逆压电效应的原子起源
DOI：
10.1209/epl/i2003-00448-8
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发表时间：
2003
期刊：
影响因子：
1.8
通讯作者：
U. Pietsch
中科院分区：
文献类型：
--
作者：
J. Davaasambuu;A. Pucher;V. Kochin;U. Pietsch
为了理解逆压电效应的原子起源，研究了α-SiO2和α-GaPO 4在E = ±8 kV/mm的外电场作用下的选择布拉格反射积分强度的变化.由于场致离子亚晶格相互位移模型不能解释实验数据，我们提出了一个考虑α-SiO2中Si和O原子间强共价键的逆压电效应模型。在这里，屏蔽外部电场的主要效果是Si-O-Si键角的变化，即刚性SiO 4四面体的旋转。同样的模型也适用于α-GaPO 4，它是α-SiO2的同构化合物。这是第一次在低温下进行类似的实验。在50 K ≤ T≤300 K之间，两种材料的压电系数d111几乎与温度无关。另一方面，场致强度的变化随温度的降低而增大。这可以解释为旋转的四面体，这是部分起源于温度下降和外部电场，分别伴随着场诱导变形的四面体。
In order to understand the atomistic origin of the inverse piezoelectric effect, the changes of integrated intensities of selected Bragg reflection of α-SiO2 and α-GaPO4 were studied, which were induced by an external high electric field of up to E = ±8 kV/mm. Because the model of the field-induced displacement of ionic sublattices against each other fails for the interpretation of experimental data, we propose a model of the inverse piezoelectric effect, which considers the strong covalent bond between Si and O atoms in α-SiO2. Here the main effect of screening the external electric field is a change in the Si-O-Si bonding angles, i.e. the rotations of rigid SiO4 tetrahedra. The same model holds for α-GaPO4, which is an isostructural compound to α-SiO2. For the first time a similar experiment was performed at low temperatures. Between 50 K ≤ T≤300 K the piezoelectric coefficient d111 of both substances behaves nearly temperature independent. On the other hand, the field-induced change of the intensities increases for decreasing temperature. This can be interpreted by the rotation of tetrahedra, which is partially originated by the temperature decrease and by the external electric field, respectively, accompanied by a field-induced deformation of tetrahedra.