The anisotropy of deformations in potassium acid phthalate crystals arising under the action of an external electric field up to 1 kV mm⁻¹ applied along the [001] polar axis was studied using X-ray diffraction methods at room temperature. Electrical conductivity was measured and rocking curves for reflections 400, 070 and 004 were obtained by time-resolved X-ray diffractometry in Laue and Bragg geometries. Two saturation processes were observed from the time dependences of the electrical conductivity. A shift in the diffraction peaks and a change in their intensity were found, which indicated a deformation of the crystal structure. Rapid piezoelectric deformation and reversible relaxation-like deformation, kinetically similar to the electrical conductivity of a crystal, were revealed. The deformation depended on the polarity and strength of the applied field. The deformation was more noticeable in the [100] direction and was practically absent in the [001] direction of the applied field. X-ray diffraction analysis revealed a disordered arrangement of potassium atoms, i.e. additional positions and vacancies. The heights of potential barriers between the positions of K⁺ ions and the paths of their possible migration in the crystal structure of potassium acid phthalate were determined. The data obtained by time-resolved X-ray diffractometry and X-ray structure analysis, along with additional electrophysical measurements, allow the conclusion that the migration of charge carriers (potassium cations) leads to lateral deformation of the crystal structure of potassium phthalate in an external electric field.

中文翻译：

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邻苯二甲酸钾晶体在外电场作用下的横向变形

在高达 1 kV mm ^-1的外部电场作用下产生的邻苯二甲酸钾晶体变形的各向异性在室温下使用 X 射线衍射方法研究沿 [001] 极轴施加的 通过劳厄和布拉格几何中的时间分辨 X 射线衍射测量电导率并获得反射 400、070 和 004 的摇摆曲线。从电导率的时间依赖性观察到两个饱和过程。发现衍射峰的移动及其强度的变化，这表明晶体结构变形。揭示了在动力学上类似于晶体的电导率的快速压电变形和可逆松弛状变形。变形取决于外加场的极性和强度。变形在 [100] 方向上更为明显，而在外加场的 [001] 方向上几乎不存在变形。X 射线衍射分析显示钾原子的无序排列，即额外的职位和空缺。确定了K ⁺离子位置之间的势垒高度及其在邻苯二甲酸钾晶体结构中可能迁移的路径。通过时间分辨 X 射线衍射法和 X 射线结构分析获得的数据以及附加的电物理测量得出的结论是，电荷载流子（钾阳离子）的迁移导致邻苯二甲酸钾晶体结构的横向变形。外电场。