Structural Defects Improve the Memristive Characteristics of Epitaxial La0.8Sr0.2MnO3‐Based Devices.

Interface‐type valence change memories (VCMs) are exciting candidates for multilevel storage in resistive random access memories (RRAM) and as artificial synapses for neuromorphic computing. Several materials have been proposed as VCM candidates and, depending on the materials and electrodes of choice, different switching mechanisms take place leading to the change in resistance. Here, the focus is on La0.8Sr0.2MnO3–δ (LSM) perovskite and, particularly, the role of its nanostructure on the memristive device performance. The nanostructural details of the layers are modified by growing LSM epitaxial thin films on different substrates, i.e., SrTiO3 (STO) and LaAlO3 (LAO), by metal‐organic chemical vapor deposition (MOCVD). An interface‐type memristive response is observed using Ti as active electrode and Pt as inert electrode. The modifications in the nanostructure of LSM (strain and dislocations) determine the memristive performance, leading to differences in cycle to cycle reproducibility and multilevel capabilities by the modification of the LSM's oxygen migration properties. The results show that nanostructure engineering is a promising approach for optimizing the performance of memristive devices, an approach which can also be extended and applied to other nanoionic electrochemical devices. [ABSTRACT FROM AUTHOR]