论文标题
调查非常规铁电$ hf_ {0.5} zr_ {0.5} o__ {2} $ - 基于Operando nanobeam X射线衍射的电容器
Investigating the Electromechanical Behavior of Unconventionally Ferroelectric $Hf_{0.5}Zr_{0.5}O_{2}$-based Capacitors Through Operando Nanobeam X-ray Diffraction
论文作者
论文摘要
了解基于Hafnia的纳米材料中铁电性的各个方面对于开发未来的非挥发记忆和逻辑设备至关重要。 Here, the unconventional and weak electromechanical response of epitaxial $La_{0.67}Sr_{0.33}MnO_{3}$/$Hf_{0.5}Zr_{0.5}O_{2}$/$La_{0.67}Sr_{0.33}MnO_{3}$ ferroelectric capacitors通过在应用电偏置期间的纳米氨X射线衍射实验提供的灵敏度研究。结果表明，原始菱形相位具有负线压电系数（$ d_ {33} $）〜 -0.5至-0.8 pm $ v^{ - 1} $。第一原理计算支持固有的负压力响应。此外，发现压电反应被抑制在强制电压之上。对于更高的电压，以及在整个电容器中DC电导率的发作，可以观察到二阶效应。在这项工作中观察到的机电反应与正常铁电体明显不同，再次强调了样品中极化转换的非常规性。
Understanding various aspects of ferroelectricity in hafnia-based nanomaterials is of vital importance for the development of future non-volatile memory and logic devices. Here, the unconventional and weak electromechanical response of epitaxial $La_{0.67}Sr_{0.33}MnO_{3}$/$Hf_{0.5}Zr_{0.5}O_{2}$/$La_{0.67}Sr_{0.33}MnO_{3}$ ferroelectric capacitors is investigated, via the sensitivity offered by nanobeam X-ray diffraction experiments during application of electrical bias. It is shown that the pristine rhombohedral phase exhibits a negative linear piezoelectric effect with piezoelectric coefficient ($d_{33}$) ~ -0.5 to -0.8 pm$V^{-1}$. First-principles calculations support an intrinsic negative piezoresponse. In addition, it is found that the piezoelectric response is suppressed above the coercive voltage. For higher voltages, and with the onset of DC conductivity throughout the capacitor, a second-order effect is observed. The electromechanical response observed in this work is clearly different from that of normal ferroelectrics, again underlining the unconventional nature of polarization switching in the samples.
