Room temperature current conduction mechanisms in Ba0.5Sr0.5TiO3 and Ba0.5Sr0.5TiO3/TiO2 multilayer memristor structures

Abstract

In this study, pure BaSrTiO3 (BST) thin films and layered BST/TiO2 thin films were fabricated on Cr/SiO2/Si substrates for a possible fourth passive device in electronics called a memristor. Radio frequency- and high-power impulse magnetron sputtering-based reactive sputtering was used for the deposition of films. While analyzing the memristor behavior by IV-t measurement at room temperature, optical, structural, surface morphology, thermal annealing effect, and current conduction mechanisms were investigated. The structures gained memristive behavior due to the oxygen vacancies displaced by the effect of annealing. As bipolar switching was observed in all memristor structures, the switching mechanism was identified as the valance change mechanism, in which conductivity is mostly provided by Poole–Frenkel and Schottky emission conduction mechanisms.