Current–Voltage Characteristics and Resistive Switching in an Epitaxial La_0.67Sr_0.33MnO₃/SrMnO₃/La_0.67Sr_0.33MnO₃ Multilayer

In the present study, we investigate the structural properties and current–voltage (I–V) characteristics of an epitaxial multilayer composed of La0.67Sr0.33MnO3 (25 nm)/SrMnO3 (70 nm)/La0.67Sr0.33MnO3 (25 nm), grown on different substrates, i.e., SrTiO3(100), LaAlO3(100), and Si(100). The used substrates not only have different chemical compositions in line with the film materials but also have different lattice parameters, which would significantly tune the material chemistry and lattice strain at the interface. Our I–V measurements reveal distinct electrical behaviors depending on the substrate. The multilayers grown on oxide SrTiO3(100) and LaAlO3(100) substrates exhibit regular I–V with slight nonlinearity at low applied voltages. In contrast, I–V in a multilayer with the Si(100) substrate exhibits large asymmetry and notable resistive switching (RS) behavior at room temperature, where a resistance ratio of around 10 between the high-resistance state (HRS) and low-resistance state (LRS) is observed. While the observed I–V behavior is sensitive to substrate-induced interfacial disorder and formation of trap bands within the band gap of SrMnO3, the present results have potential applications in future memory and memristive devices.