Theoretical-experimental correlation of magnetic behavior in diluted magnetic TiO2 nanotubes for memristive type applications

The system consists of Co diluted in TiO2 nanotubes obtained by electrochemical anodization process over Co/Ti foils, with NH4F, distilled water, and ethylene glycol. Cobalt was deposited on the Ti foils (99.99% purity) via DC magnetron sputtering at room temperature. The anodization process establishes the percentage of Co dilution into the TiO2 matrix around 0.67 wt. % through EDXS measurements. The nanostructure of the nanotubes was evidenced by the SEM micrographs. These measurements permitted the observation of nanotubes with a hollow hexagonal morphology. Nevertheless, we model this nanotube as a cylindrical-hollow nanotube with inner and outer radii ∼15 and 30 nm, respectively, and the height is 96.6 nm according to the SEM micrographs. The I–V curves show a bipolar resistive behavior with the resistance ratio high resistance state/low resistance state remaining essentially stable, around 1.22. The results obtained through Ubermag environment simulations were compared with experimental magnetization measurements as a function of the magnetic field at room temperature for Co-doped TiO2 nanotubes. This comparison enabled their analysis as a diluted magnetic material for potential applications in information storage memories.