Resistive switching in Strontium iridate based thin films

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...

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Detalles Bibliográficos
Autores: Fuentes, Víctor, Vasić, Borislav, Konstantinović, Z., Martínez Perea, Benjamín, Balcells, Lluis, Pomar, Alberto
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2020
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/230577
Acceso en línea:http://hdl.handle.net/10261/230577
Access Level:acceso abierto
Palabra clave:Resistive switching
Metal-insulator transitions
SrIrO3
Sr2IrO4
Conductive atomic force microscopy
Iridate thin films
Descripción
Sumario: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.