R&D: TiO2 and TiO2:Co Nanostructures for Enhanced NVM, Insights into Surface Modification

Ceramics International has published an article written by Heiddy P. Quiroz, Universidad Nacional de Colombia – Bogotá, Dpto. de Física, Grupo de Materiales Nanoestructurados y Sus Aplicaciones, Cra. 30 No. 45-03 Edificio 404 Yu Takeuchi Lab, 121C / 121B-1 Ciudad Universitaria, Bogotá, 110001, Colombia, Jorge A. Calderón, Universidad Nacional de Colombia – Bogotá, Dpto. de Física, Grupo de Materiales Nanoestructurados y Sus Aplicaciones, Cra. 30 No. 45-03 Edificio 404 Yu Takeuchi Lab, 121C / 121B-1 Ciudad Universitaria, Bogotá, 110001, Colombia, and Grupo de investigación en Nanotecnología, Bioingeniería y Transferencia Tecnológica, Cluster in Convergent Sciences and Technologies, Universidad Central, Colombia, Y. Porras Ramírez, and A. Dussan, Universidad Nacional de Colombia – Bogotá, Dpto. de Física, Grupo de Materiales Nanoestructurados y Sus Aplicaciones, Cra. 30 No. 45-03 Edificio 404 Yu Takeuchi Lab, 121C / 121B-1 Ciudad Universitaria, Bogotá, 110001, Colombia.

Abstract: “In this work, we investigate the synthesis of TiO₂ and TiO₂:Co nanostructures via Chemical Bath Deposition (CBD), electrochemical anodization, and DC magnetron sputtering. A comparative analysis is presented regarding the growth mechanisms and morphology of various nanostructures, including nanoflowers, nanotubes, and thin films. The structural properties, with a particular focus on the anatase and rutile polymorphic phases, were characterized using XRD, Raman, and IR spectroscopy, while thermal-induced phase transformations were evaluated after synthesis. The influence of annealing on crystallite size was studied, revealing a direct correlation between annealing temperature and crystal growth in anodized nanotubes. Morphological and topographic analyses, carried out via HR-SEM, AFM, and TEM, highlighted the formation of nanorod-based or dendritic nanoflowers (130.2 ± 12.5 nm) and nanotubes with an average length of 6.58 ± 0.74 μm. Thin films exhibited grain and island structures following the Movchan-Demchishin model. Finally, the potential of TiO₂:Co nanostructures for applications in spintronic devices and diluted magnetic semiconductors was explored, with I-V measurements demonstrating typical SET and RESET processes associated with resistive switching behavior.“