作　　者： ;

机构地区： 北京大学物理学院

出　　处： 《物理学进展》 2012年第5期233-283,共51页

摘　　要： 在多种氧化物材料和器件中观察到了可重复、可复制和可反转的电致电阻变换或电阻开关(resistance switching)行为,这种行为可能应用于不丢失信息存储,因此得到了广泛关注。由于材料和样品结构的多样性和观察到的氧化物电致电阻变换效应显现出多层次的行为,这为分析驱动机制带来了复杂性。目前,提出了多种假设来解释氧化物电阻变换效应,而最广泛使用的是的氧空位扩散(负离子迁移)形成导电细丝的模型,而导电细丝的形成和破坏对应于电阻变换效应的"开"与"关"。然而,分析不同实验组发表的大量实验结果清楚表明,氧化物电致电阻变换存在着不依赖电场极性、电致电阻变换下锰氧化物材料的电阻下降以及材料离子化学态的发生变化等重要特征。这些实验结果展示的共有主要特征清楚说明,氧化物电致电阻变换的机制应该不是电场下氧空位迁移形成导电细丝模型所描述的。认真分析和可调整超导、磁学性质等结果都表明,我们应该考虑载流子注入效应。虽然彻底理解氧化物电致电阻变换行为仍然需要进一步的研究工作,但载流子注入与自束缚载流子观点描绘出了相当合理的图像,来理解观察到的大量不同研究组发表的多种多样氧化物电致电阻变换行为实验结果。综合来看,外加电场下氧化物的电阻变换与引起的相关现象可能会开辟出一个奇异的全新研究与应用领域。 Resistance switching between low resistance states and high resistance states upon triggering by externally applied electrical field has been observed in a number of oxide materials sandwiched with electrodes. Owing to the excellent repeatability, reproducibility and recoverability, this resis- tance switching behavior in oxide devices has attracted much attention for potential applications in nonvolatile memory technologies. In spite of observed resistive switching in a wide variety of oxides, substantial challenges in revealing the underlying mechanisms remain available due to the diversity of resistance switching behaviors and the variety of materials microstructures. At present, quite a few models have been proposed to explain various resistance switching behaviors observed in individual materials, however, the most recognized model is associated with the forma- tion and destruction of conducting filaments generated from anion-migration of oxygen vacancies. So far available experimental data reported by different groups demonstrated that oxygen-vacancy （anion） migration assumption is inefficient to explain a number of observed phenomena includ- ing the polar independence, the relaxation of resistance and variation of ionic chemical valence States during the switching. The major and common characters of experimental results illustrate that either the unipolar or bipolar resistance switching in oxides may not be the consequence of ON/OFF sequence of conducting filaments. Instead, results obtained in oxide hetero-layer junc- tions suggest that the carrier injection effect should be taken into account in order to explain those scattered resistance switching phenomena. The connection between the resistance switching and metal-insulator transition in doped manganites, the tunable superconducting behaviors, and magnetization responses during the resistance switching reflect the substantial roles of injected carriers in modulating the intrinsic transport properties of the bulk functional oxide

关 键 词： 氧化物电致电阻变换 载流子注入 自束缚载流子 氧空位移动

领　　域： [理学] [理学]