Optical and magnetic investigation of Co-doped-TiO2: various morphologies of titanium dioxide nanostructures

Abstract

In this work, TiO 2 nanoparticles and nanorods have been synthesized and their structural properties have been investigated in different preparation conditions. The effect of cobalt doping (in different molar ratios of 6, 12, 18 and 24) on physical properties of nanoparticles was studied. Un-doped and cobalt doped titanium dioxide nanoparticles was prepared through the sol-gel method. Nanostructures were characterized by using X-ray diffraction and scanning electron microscopy techniques. The effect of cobalt doping on the magnetic properties is also investigated by vibrating sample magnetometer. It confirmed that cobalt doped TiO 2 nanoparticles show paramagnetic behavior and their magnetic susceptibilities enhanced by increasing the doping level. Results show that increasing of cobalt doping produce a CoTiO 3 phase and the particle sizes increase.

Surface Magnetism of Cobalt-Doped Anatase TiO2 Nanopowders

“…Considering the complicated competing exchange interactions between 3d ions, a variety of spin structures can be realized with the involvement of defects (e.g., vacancies with an unpaired electron), which are capable of changing significantly the physical and chemical properties of the material both on the surface and in the bulk. Cobalt has proved to be an effective doping element significantly modifying the electronic and magnetic properties of titanium dioxide. − The TiO 2 :Co-based systems demonstrate ferromagnetic behavior with the Curie temperature above room temperature. According to the papers, − defects observable in titanium dioxide, preferentially in the anion sublattice, play a key role in such behavior.…”