论文标题
氧气空位成核铁电中的带电域壁
Oxygen vacancies nucleate charged domain walls in ferroelectrics
论文作者
论文摘要
我们使用第一原理计算研究了氧空位空位对铁电batio $ _3 $形成的氧气空缺的影响。我们表明，空缺在晶体平面上组装是有利的，并且这种聚类伴随着带电域壁的形成。域壁具有负绑定电荷，可以补偿空位的标称正电荷，并导致墙壁上的自由电荷密度消失。这与带正电荷的域壁形成鲜明对比，后者几乎完全由大量的免费电荷弥补。因此，结果解释了两种类型的域壁的电子电导率差异，以及铁电机中带电域壁的通用率。此外，空置驱动域壁的形成的明确演示意味着可以通过自下而上的设计来实现特定的带电域墙配置，以在基于域墙的信息处理中使用。
We study the influence of oxygen vacancies on the formation of charged 180$^\circ$ domain walls in ferroelectric BaTiO$_3$ using first principles calculations. We show that it is favorable for vacancies to assemble in crystallographic planes, and that such clustering is accompanied by the formation of a charged domain wall. The domain wall has negative bound charge, which compensates the nominal positive charge of the vacancies and leads to a vanishing density of free charge at the wall. This is in contrast to the positively charged domain walls, which are nearly completely compensated by free charge from the bulk. The results thus explain the experimentally observed difference in electronic conductivity of the two types of domain walls, as well as the generic prevalence of charged domain walls in ferroelectrics. Moreover, the explicit demonstration of vacancy driven domain wall formation implies that specific charged domain wall configurations may be realized by bottom-up design for use in domain wall based information processing.
