arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1910.02447cond-mat.mtrl-sci
收藏

铁弹畴壁厚度与原子环境的关系

Atomic-environment-dependent thickness of ferroelastic domain walls

Mingqiang Li, Xiaomei Li, Yuehui Li, Heng-Jui Liu, Ying-Hao Chu, Peng Gao

摘要:

畴壁由于其独特的性质和在未来纳米电子学中的潜在应用而在铁电体中引起越来越多的关注。然而,铁弹畴壁的厚度仍然难以捉摸,由于在实验表征的挑战。在这里,我们确定的铁弹畴壁的原子结构,并精确地测量在皮米级的偏振和畴壁厚度,使用像差校正的扫描透射电子显微镜中的环形明场成像。我们发现在PbZr0.2Ti0.8O3和PbTiO3薄膜中的畴壁厚度通常约为一个晶胞,在此范围内氧八面体畸变行为与第一性原理计算非常一致.值得注意的是,还观察到约两个晶胞厚度的更宽的畴壁,因为这些畴壁与位错耦合并经历压应变。这些结果表明,铁弹畴壁的厚度高度依赖于它们的原子环境。这项研究可以帮助我们理解过去有争议的实验结果,并提供进一步的见解,通过应变工程控制畴壁在纳米电子学中的可能应用。

英文摘要:

Domain walls are of increasing interest in ferroelectrics because of their unique properties and potential applications in future nanoelectronics. However, the thickness of ferroelastic domain walls remains elusive due to the challenges in experimental characterization. Here, we determine the atomic structure of ferroelastic domain walls and precisely measure the polarization and domain wall thickness at picometer scale using annular bright field imaging in an aberration-corrected scanning transmission electron microscope. We find that the domain wall thickness in PbZr0.2Ti0.8O3 and PbTiO3 thin films is typically about one-unit cell, across which the oxygen octahedron distortion behavior is in excellent agreement with first principles calculations. Remarkably, wider domain walls about two-unit cells in thickness are also observed for those domains walls are coupled with dislocations and underwent a compressive strain. These results suggest that the thickness of ferroelastic domain walls highly depends on their atomic environments. This study can help us to understand the past debatable experimental results and provide further insights into control of domain walls via strain engineering for their possible applications in nanoelectronics.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑