The mechanism of forming-free bipolar resistive switching in a Zr/CeO x /Pt device was investigated. High-resolution transmission electron microscopy and energy-dispersive spectroscopy analysis indicated the formation of a ZrO y layer at the Zr/CeO x interface. X-ray diffraction studies of CeO x films revealed that they consist of nano-polycrystals embedded in a disordered lattice. The observed resistive switching was suggested to be linked with the formation and rupture of conductive filaments constituted by oxygen vacancies in the CeO x film and in the nonstoichiometric ZrO y interfacial layer. X-ray photoelectron spectroscopy study confirmed the presence of oxygen vacancies in both of the said regions. In the low-resistance ON state, the electrical conduction was found to be of ohmic nature, while the high-resistance OFF state was governed by trap-controlled space charge-limited mechanism. The stable resistive switching behavior and long retention times with an acceptable resistance ratio enable the device for its application in future nonvolatile resistive random access memory (RRAM).
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机译:研究了Zr / CeO x / Pt器件中无形成双极电阻开关的机理。高分辨率透射电子显微镜和能量色散光谱分析表明在Zr / CeO x界面上形成了ZrO y层。 CeO x薄膜的X射线衍射研究表明,它们由嵌入无序晶格中的纳米多晶体组成。建议观察到的电阻转换与由CeO x膜和非化学计量的ZrO y界面层中的氧空位构成的导电丝的形成和破裂有关。 X射线光电子能谱研究证实了在所述两个区域中都存在氧空位。在低电阻导通状态下,发现导电具有欧姆性,而高电阻关断状态则由陷阱控制的空间电荷限制机制控制。稳定的电阻开关性能和较长的保留时间以及可接受的电阻比使该器件得以在未来的非易失性电阻随机存取存储器(RRAM)中应用。
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