ACS Appl Mater Interfaces. 2018 Jun 6;10(22):19002-19009. doi: 10.1021/acsami.8b01153. Epub 2018 May 23.
Hybrid nanostructures can show enormous potential in different areas because of their unique structural configurations. Herein, Fe@AlO hybrid nanotubes are constructed via a homogeneous coprecipitation method followed by subsequent annealing in a reducing atmosphere. The introduction of zero band gap Fe nanocrystals in the wall of ultrawide band gap AlO insulator nanotubes results in the formation of charge trap centers, and correspondingly a single hybrid nanotube-based two-terminal device can show reversible negative resistive switching (RS) characteristics with symmetrical negative differential resistance (NDR) at relatively high operation bias voltages. At a large bias voltage, holes and electrons can be injected into traps at two ends from electrodes, respectively, and then captured. The bias voltage dependence of asymmetrical filling of charges can lead to a reversible variation of built-in electromotive force, and therefore the symmetrical negative RS with NDR arises from two reversible back-to-back series bipolar RS. At a low readout voltage, the single Fe@AlO hybrid nanotube can show an excellent nonvolatile memory feature with a relatively large switching ratio of ∼30. The bias-governed reversible negative RS with superior stability, reversibility, nondestructive readout, and remarkable cycle performance makes it a potential candidate in next-generation erasable nonvolatile resistive random access memories.
由于其独特的结构配置，混合纳米结构在不同领域显示出巨大的潜力。在此，通过均相共沉淀法制备了 Fe@AlO 混合纳米管，然后在还原气氛中进行退火。在超宽带隙 AlO 绝缘体纳米管的壁中引入零带隙 Fe 纳米晶体导致形成电荷俘获中心，相应地，基于单个混合纳米管的两端器件可以在相对较高的工作偏压下显示出可逆的负电阻开关（RS）特性和对称的负微分电阻（NDR）。在大偏压下，空穴和电子可以分别从电极注入到两端的陷阱中，然后被捕获。电荷的不对称填充对偏压的依赖性导致内置电动势的可逆变化，因此具有 NDR 的对称负 RS 来自两个可逆的背靠背串联双极 RS。在较低的读出电压下，单个 Fe@AlO 混合纳米管可以表现出优异的非易失性存储特性，开关比约为 30。具有优越稳定性、可逆性、非破坏性读出和显著循环性能的偏压控制的可逆负 RS 使其成为下一代可擦除非易失性阻变随机存取存储器的潜在候选者。
