Nanoscale Ring-Shaped Conduction Channels with Memristive Behavior in BiFeO₃ Nanodots.

Zhongwen Li,Guofu Zhou,Zhen Fan

doi:10.3390/nano8121031

Abstract

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.

Highlights

Nanoscale conduction channels with ring-like shapes are of particular interest in nanoscience owing to their broad application prospects
The structural characterizations of the BFO nanodots can be found in our previous work [27], while this work mainly deals with the electrical characterizations
We have observed nanoscale ring-shaped conduction channels with memristive behavior in BFO nanodots prepared by ion beam etching

Summary

Introduction

Nanoscale conduction channels with ring-like shapes are of particular interest in nanoscience owing to their broad application prospects. They may be used to carry persistent currents [1,2]. When the ring-shaped conduction channels are made of magnetic materials, they may be used for constructing magnetic tunnel junctions with reduced power consumption and enhanced thermal stability [3,4]. We aim to achieve such kind of nanoscale conduction channels possessing both ring-like shapes and memristive properties, which may have potential applications in high-density, low-power memory devices

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