Abstract We report on the local electrical properties, measured by conductive atomic force microscopy, of the Iridate-based Srn+1IrnO3n+1 family of thin films, in particular by comparing the n = 1, Sr2IrO4, and the n = ∞, SrIrO3, phases. We analyze the different resistive switching behavior as a function of the pristine electronic properties of the films. We will show that, for films exhibiting insulating behavior, i.e., films of the n = 1 phase or films below 3 nm of thickness for the n = ∞ phase, hysteretic I–V curves with a sharp transition into a low resistance state (LRS), i.e. an abrupt increase of the current intensity, is detected above a well-defined threshold voltage. This suggests a resistive switching behavior associated to the jump between two resistance states that may be correlated to the activation energy, Δ, obtained by fitting the temperature dependence of the resistivity to a thermal activated Arrhenius law, ρ (T) ~ ρ0exp(−Δ/kBT). On the other hand, thicker samples of the n = ∞ phase exhibit a semimetallic character and I–V curves show progressive changes of the local resistance without a clearly defined threshold voltage. Kelvin Probe Force Microscopy based measurements confirmed that, concomitantly to the resistive switching, an evolution of the electronic states at the surface takes place that may be associated to the migration of oxygen vacancies promoted by the electrical fields under the AFM tip.

中文翻译：

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基于铱酸锶的薄膜中的电阻开关

摘要 我们报告了由导电原子力显微镜测量的基于铱酸盐的 Srn+1IrnO3n+1 系列薄膜的局部电学特性，特别是通过比较 n = 1、Sr2IrO4 和 n = ∞、SrIrO3、阶段。我们将不同的电阻开关行为作为薄膜原始电子特性的函数进行分析。我们将证明，对于表现出绝缘行为的薄膜，即 n = 1 相的薄膜或厚度低于 3 nm 的 n = ∞ 相的薄膜，滞后 I-V 曲线急剧转变为低电阻状态（LRS )，即电流强度的突然增加，在明确定义的阈值电压之上被检测到。这表明与两个电阻状态之间的跳跃相关的电阻切换行为可能与活化能有关，Δ，通过将电阻率的温度依赖性与热激活的阿伦尼乌斯定律 ρ (T) ~ ρ0exp(-Δ/kBT) 拟合而获得。另一方面，n = ∞ 相的较厚样品表现出半金属特性，I-V 曲线显示局部电阻的逐渐变化，而没有明确定义的阈值电压。基于开尔文探针力显微镜的测量证实，伴随着电阻切换，发生了表面电子态的演变，这可能与 AFM 尖端下的电场促进的氧空位迁移有关。n = ∞ 相的较厚样品表现出半金属特性，I-V 曲线显示局部电阻的逐渐变化，而没有明确定义的阈值电压。基于开尔文探针力显微镜的测量证实，伴随着电阻切换，发生了表面电子态的演变，这可能与 AFM 尖端下的电场促进的氧空位迁移有关。n = ∞ 相的较厚样品表现出半金属特性，I-V 曲线显示局部电阻的逐渐变化，而没有明确定义的阈值电压。基于开尔文探针力显微镜的测量证实，伴随着电阻切换，发生了表面电子态的演变，这可能与 AFM 尖端下的电场促进的氧空位迁移有关。