The influence of transition metals (Fe, Co) on the structural, magnetic and optical properties of TiO2 nanoparticles synthesized by the hydrothermal method

The search for completely new dilute magnetic semiconductor (DMS) materials with room temperature (RT) ferromagnetism, as well as designing and modification in existing DMS materials are some important and recent issues regarding DMSs. The achievement of RT ferromagnetism in these materials is itself a great challenge. To fight against this challenge, different transition metals are doped in TiO2 to make it ferromagnetic The present research also focuses on TiO2-based diluted magnetic semiconductors doped with Co and Fe. These transition metals are chosen because they have high magnetic moment of 3 and 5 µB, respectively. The chemical route, i.e., hydrothermal method, was used to synthesize four samples, i.e., (i) undoped TiO2, (ii) 10% Co-doped TiO2, (iii) 5% Co-doped TiO2 and 5% Fe-doped TiO2, (iv) 10% Fe-doped TiO2. These synthesized nanoparticles were then examined by X-ray-diffractometer (XRD), Fourier transformed infrared (FTIR), scanning electron microscope (SEM), vibrating sample magnetometer (VSM) and UV–visible spectroscopy (UV–Vis) to investigate their crystalline structure and morphological, magnetic and optical properties, respectively. XRD study revealed the anatase phase of TiO2. The anatase phase was further confirmed via FTIR analysis. SEM micrographs of nanoparticles showed agglomerated morphology of TiO2. Magnetic study revealed the RT ferromagnetic behaviors of all as-prepared nanoparticles except undoped TiO2. UV–visible spectroscopy revealed that the optical band gap can be reduced by the addition of transition metal ions into TiO2.