Probing electron density across Ar~+ irradiation-induced self-organized TiO_(2-x) nanochannels for memory application

摘要

The variation of electron density in TiO_(2-x) nanochannels, exhibiting resistive switching phenomenon, produced by Ar~+ ion-irradiation at the threshold fluence of 5 × 10~(16) ions/cm~2 is demonstrated by X-ray reflectivity (XRR). The transmission electron microscopy reveals the formation of nanochannels, while the energy dispersive X-ray spectroscopy confirms Ti enrichment near the surface due to ion-irradiation, in consistent with the increase in electron density by XRR measurements. Such a variation in Ti concentration indicates the evolution of oxygen vacancies (OVs) along the TiO_(2-x) nanochannels, and thus paves the way to explain the operation and performance of the Pt/TiO_(2-x)/Pt-based memory devices via OV migration.