Influence of chemical equilibrium in introduced oxygen vacancies on resistive switching in epitaxial Pt-CeO2 system
Abstract
We investigate the introduction of oxygen vacancies by the interaction of Pt with CeO2(111) (ceria) thin epitaxial film grown on Cu(111) and the influence of the vacancies on resistive switching behavior. For this purpose, we used X-ray photoelectron spectroscopy and conductive atomic force microscopy.
We found out that after Pt deposition, the ceria film was partially reduced. By our estimation, the reduction occurs not only at the Pt/CeO2 interface, but also on the surface of the ceria film which is not covered by Pt, after Pt deposition and annealing.
A different distribution of oxygen vacancies in the film proves to have an influence on the resistance switching process of the film. Finally, the proper balance between the reduced and the unreduced species in order to obtain relatively stable repeatable resistance switch with clear resistance window is discussed.