Understanding the influence of defects and surface chemistry on ferroelectric switching: a ReaxFF investigation of BaTiO3
Understanding the influence of defects and surface chemistry on ferroelectric switching: a ReaxFF investigation of BaTiO3
复制标题
DOI：
10.1039/c9cp02955a
复制
发表时间：
2019-09-07
影响因子：
3.3
通讯作者：
van Duin, Adri C. T.
中科院分区：
文献类型：
--
作者：
Akbarian, Dooman;Yilmaz, Dundar E.;van Duin, Adri C. T.
钛酸钡(BaTiO3)等铁电材料因其优异的性能在纳米电子器件中有着广泛的应用。在这项研究中，我们开发了一个易于扩展的原子ReaxFF反应力场，它可以捕捉到由场和温度引起的铁电磁滞以及由表面化学和体缺陷引起的相应变化。利用我们的力场，我们能够重现和解释一些实验观察：(1)存在4.8 nm的临界厚度，低于该厚度铁电性在BaTiO_3中消失；(2)BaTiO_3中的氧空位(OV)的迁移和聚集，以及由于OV而导致的极化和居里温度的降低；(3)与表面化学的相互作用影响铁电开关和极化幅度。这一新的计算工具为预测能量转换、电子和神经形态系统中的现实铁电界面开辟了广泛的可能性。
Ferroelectric materials such as barium titanate (BaTiO3) have a wide range of applications in nano scale electronic devices due to their outstanding properties. In this study, we developed an easily extendable atomistic ReaxFF reactive force field for BaTiO3 that can capture both its field- and temperature-induced ferroelectric hysteresis and corresponding changes due to surface chemistry and bulk defects. Using our force field, we were able to reproduce and explain a number of experimental observations: (1) the existence of a critical thickness of 4.8 nm below which ferroelectricity vanishes in BaTiO3; (2) migration and clustering of oxygen vacancies (OVs) in BaTiO3 and a reduction in the polarization and the Curie temperature due to the OVs; (3) domain wall interaction with the surface chemistry to influence the ferroelectric switching and polarization magnitude. This new computational tool opens up a wide range of possibilities for making predictions for realistic ferroelectric interfaces in energy-conversion, electronic and neuromorphic systems.