Li Zhongwen, Fan Zhen, Zhou Guofu
Institute for Advanced Materials, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China.
Guangdong Provincial Key Laboratory of Optical Information Materials and Technology, South China Academy of Advanced Optoelectronics, South China Normal University, Guangzhou 510006, China.
Nanomaterials (Basel). 2018 Dec 11;8(12):1031. doi: 10.3390/nano8121031.
Nanoscale ring-shaped conduction channels with memristive behavior have been observed in the BiFeO₃ (BFO) nanodots prepared by the ion beam etching. At the hillside of each individual nanodot, a ring-shaped conduction channel is formed. Furthermore, the conduction channels exhibit memristive behavior, i.e., their resistances can be continuously tuned by the applied voltages. More specifically, a positive (negative) applied voltage reduces (increases) the resistance, and the resistance continuously varies as the repetition number of voltage scan increases. It is proposed that the surface defects distributed at the hillsides of nanodots may lower the Schottky barriers at the Pt tip/BFO interfaces, thus leading to the formation of ring-shaped conduction channels. The surface defects are formed due to the etching and they may be temporarily stabilized by the topological domain structures of BFO nanodots. In addition, the electron trapping/detrapping at the surface defects may be responsible for the memristive behavior, which is supported by the surface potential measurements. These nanoscale ring-shaped conduction channels with memristive behavior may have potential applications in high-density, low-power memory devices.
在通过离子束蚀刻制备的BiFeO₃（BFO）纳米点中观察到了具有忆阻行为的纳米级环形传导通道。在每个单独的纳米点的山坡处，形成了一个环形传导通道。此外，这些传导通道表现出忆阻行为，即它们的电阻可以通过施加的电压连续调节。更具体地说，施加正（负）电压会降低（增加）电阻，并且随着电压扫描重复次数的增加，电阻会持续变化。据推测，分布在纳米点山坡处的表面缺陷可能会降低Pt尖端/BFO界面处的肖特基势垒，从而导致环形传导通道的形成。表面缺陷是由于蚀刻形成的，并且它们可能会被BFO纳米点的拓扑畴结构暂时稳定下来。此外，表面缺陷处的电子俘获/去俘获可能是忆阻行为的原因，表面电位测量结果支持了这一点。这些具有忆阻行为的纳米级环形传导通道可能在高密度、低功耗存储器件中具有潜在应用。
