Characterization of Titanium-doped Cobalt Ferrite Nanostructures Synthesized by Hydrothermal Method

Abstract

In this work, titanium-doped cobalt ferrite (Ti_xCo_1-xFe₂O₄) nanostructures were successfully synthesized via a hydrothermal method, and the influence of titanium content on their structural properties was systematically investigated. The synthesis employed cobalt nitrate, iron nitrate, and titanium isopropoxide as precursors in an alkaline medium, followed by hydrothermal treatment at 150–220°C and subsequent calcination at 400–450°C. The formation of a single-phase cubic spinel structure was confirmed without secondary phases, while peak shifting and broadening with increasing titanium doping indicated lattice expansion and a reduction in crystallite size from 25 nm to 12 nm. The characteristic metal-oxygen vibrational bands of the spinel structure were revealed, with shifts toward lower wavenumbers upon Ti substitution, confirming successful lattice incorporation. Well-crystallized particles with octahedral morphology was shown, exhibiting exposed (111) and (100) facets, while semi-spherical granular particles in the 20–50 nm range were revealed with surface roughness potentially beneficial for catalytic applications. The observed structural modifications, including decreased crystallinity, increased lattice defects, and enhanced porosity with higher titanium content, are attributed to ionic radius differences and the redistribution of cations among tetrahedral and octahedral sites. These findings demonstrate that the hydrothermal method is effective for producing high-purity titanium-doped cobalt ferrite nanostructures with tunable structural properties, paving the way for their application in magnetic, electronic, and biomedical technologies.