Bipolar resistive switching in Pt/RNiO3/Nb-doped SrTiO3 heterostructures
Tay, Nicole Zhou Lin
Date of Issue2017-04-05
School of Materials Science and Engineering
In the recent years, rare earth perovskite nickelates (RNiO3) have attracted much attention due to its unique physical properties that cause its electronic structures to be sensitive to carrier density and bandwidth. With such sensitivity, there would be lots of possible applications using such materials. This project focuses on using Gadolinium (Gd) as the rare earth element in perovskite nickelates. Our data suggested that the migration of the oxygen vacancies alters the interfacial barrier at the GdNiO3/Nb-doped SrTiO3 interface and inducing a resistive switching behaviour. In addition, an ON/OFF ratio around 104 at room temperature was observed in the Pt/GdNiO3 (2 mTorr)/Nb-doped SrTiO3 heterostructures. The investigation of the resistive switching behaviour due to the oxygen vacancies concentration in GdNiO3 was also conducted in this study. Through varying the deposition oxygen pressures, the GdNiO3 films reflected a change in the resistive switching properties of the heterostructures. Our results proved that migration of the oxygen vacancies was responsible for the resistive switching behaviour in the device fabricated in this project. The device has also shown good data retention and fatigue performances. With the results obtained in this study, it has provided us with cues to the potential application of the switching mechanism of resistive switching memory cells of perovskite nickelates as a a non-volatile memory.
Final Year Project (FYP)
Nanyang Technological University